Liquid crystal composition and liquid crystal display device

ABSTRACT

Provided are a liquid crystal composition satisfying at least one of characteristics including a high maximum temperature, a low minimum temperature, small viscosity, suitable optical anisotropy and large negative dielectric anisotropy, or the liquid crystal composition having a suitable balance regarding at least two of the above characteristics; and an AM device including the composition. The liquid crystal composition contains a specific compound having large negative dielectric anisotropy as a first component, and a specific compound having small viscosity as a second component, and may contain a specific component having high maximum temperature or small viscosity as a third component, a specific component having negative dielectric anisotropy as a fourth component, or a specific compound having a polymerizable group as an additive.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority benefit of Japanese applicationserial no. 2016-163436, filed on Aug. 24, 2016, and Japanese applicationserial no. 2017-039118, filed on Mar. 2, 2017. The entirety of each ofthe above-mentioned patent applications is hereby incorporated byreference herein and made a part of this specification.

TECHNICAL FIELD

The invention relates to a liquid crystal composition, a liquid crystaldisplay device including the composition, and so forth. In particular,the invention relates to a liquid crystal composition having negativedielectric anisotropy, and a liquid crystal display device that includesthe composition and has a mode such as an IPS mode, a VA mode, an FFSmode and an FPA mode. The invention also relates to a polymer sustainedalignment mode liquid crystal display device.

BACKGROUND ART

In a liquid crystal display device, a classification based on anoperating mode for liquid crystal molecules includes a phase change (PC)mode, a twisted nematic (TN) mode, a super twisted nematic (STN) mode,an electrically controlled birefringence (ECB) mode, an opticallycompensated bend (OCB) mode, an in-plane switching (IPS) mode, avertical alignment (VA) mode, a fringe field switching (FFS) mode and afield-induced photo-reactive alignment (FPA) mode. A classificationbased on a driving mode in the device includes a passive matrix (PM) andan active matrix (AM). The PM is classified into static, multiplex andso forth, and the AM is classified into a thin film transistor (TFT), ametal insulator metal (MIM) and so forth. The TFT is further classifiedinto amorphous silicon and polycrystal silicon. The latter is classifiedinto a high temperature type and a low temperature type based on aproduction process. A classification based on a light source includes areflective type utilizing natural light, a transmissive type utilizingbacklight and a transflective type utilizing both the natural light andthe backlight.

The liquid crystal display device includes a liquid crystal compositionhaving a nematic phase. The composition has suitable characteristics. AnAM device having good characteristics can be obtained by improvingcharacteristics of the composition. A relationship between two aspectsof the above characteristics is summarized in Table 1 below. Thecharacteristics of the composition will be further described based on acommercially available AM device. A temperature range of the nematicphase relates to a temperature range in which the device can be used. Apreferred maximum temperature of the nematic phase is about 70° C. orhigher, and a preferred minimum temperature of the nematic phase isabout −10° C. or lower. Viscosity of the composition relates to aresponse time in the device. A short response time is preferred fordisplaying moving images on the device. A shorter response time even byone millisecond is desirable. Accordingly, small viscosity in thecomposition is preferred. Small viscosity at a low temperature isfurther preferred.

TABLE 1 Characteristics of Composition and AM Device Characteristics No.of Composition Characteristics of AM Device 1 Wide temperature range ofWide usable temperature range a nematic phase 2 Small viscosity Shortresponse time 3 Suitable optical anisotropy Large contrast ratio 4 Largepositive or negative Low threshold voltage, small electric dielectricanisotropy power consumption and large contrast ratio 5 Large specificresistance Large voltage holding ratio and large contrast ratio 6 Highstability to ultraviolet Long service life light and heat

Optical anisotropy of the composition relates to a contrast ratio in thedevice. According to a mode of the device, large optical anisotropy orsmall optical anisotropy, more specifically, suitable optical anisotropyis required. A product (Δn×d) of the optical anisotropy (Δn) of thecomposition and a cell gap (d) in the device is designed so as tomaximize the contrast ratio. A suitable value of a product depends on atype of the operating modes. The suitable value is in the range of about0.30 micrometer to about 0.40 micrometer in a device having the VA mode,and is in the range of about 0.20 micrometer to about 0.30 micrometer ina device having the IPS mode or the FFS mode. In the above cases, acomposition having large optical anisotropy is preferred for a devicehaving a small cell gap. Large dielectric anisotropy in the compositioncontributes to a low threshold voltage, a small electric powerconsumption and a large contrast ratio in the device. Accordingly, thelarge dielectric anisotropy is preferred. Large specific resistance inthe composition contributes to a large voltage holding ratio and thelarge contrast ratio in the device. Accordingly, a composition havingthe large specific resistance in an initial stage is preferred. Afterthe device has been used for a long period of time, a composition havingthe large specific resistance is preferred. The stability of thecomposition to ultraviolet light or heat relates to a service life ofthe device. In the case where the stability is high, the device has along service life. Such characteristics are preferred for an AM deviceused in a liquid crystal projector, a liquid crystal television and soforth.

In a general-purpose liquid crystal display device, vertical alignmentof liquid crystal molecules is achieved by a specific polyimidealignment film. In a polymer sustained alignment (PSA) mode liquidcrystal display device, a polymer is combined with the alignment film.First, a composition to which a small amount of a polymerizable compoundis added is injected into the device. Then, the composition isirradiated with ultraviolet light while voltage is applied betweensubstrates of the device. The polymerizable compound is polymerized toform a network structure of the polymer in the composition. In thecomposition, alignment of liquid crystal molecules can be controlled bythe polymer, and therefore the response time of the device is shortenedand also image persistence is improved. Such an effect of the polymercan be expected for a device having the mode such as the TN mode, theECB mode, the OCB mode, the IPS mode, the VA mode, the FFS mode and theFPA mode.

A composition having positive dielectric anisotropy is used in an AMdevice having the TN mode. A composition having negative dielectricanisotropy is used in an AM device having the VA mode. A compositionhaving the positive or negative dielectric anisotropy is used in an AMdevice having the IPS mode or the FFS mode. A composition havingpositive or negative dielectric anisotropy is used for an AM devicehaving the polymer sustained alignment mode. A compound contained in afirst component according to the invention is disclosed in Patentliterature No. 1 or 2 described below.

CITATION LIST Patent Literature

Patent literature No. 1: JP 2011-136913 A.

Patent literature No. 2: JP 2011-136914 A.

SUMMARY OF INVENTION

The invention provides a liquid crystal composition satisfying at leastone of characteristics including a high maximum temperature of a nematicphase, a low minimum temperature of the nematic phase, small viscosity,suitable optical anisotropy, large negative dielectric anisotropy, largespecific resistance, high stability to ultraviolet light and highstability to heat. The invention further provides a liquid crystalcomposition having a suitable balance regarding to at least two of theabove characteristics. The invention further provides a liquid crystaldisplay device including the composition. The invention further providesan AM device having characteristics including a short response time, ahigh voltage holding ratio, a low threshold voltage, a large contrastratio and a long service life.

The invention concerns a liquid crystal composition that has negativedielectric anisotropy, and contains at least one compound selected fromthe group of compounds represented by formula (1) as a first component,and at least one compound selected from the group of compoundsrepresented by formula (2) as a second component, and a liquid crystaldevice including the composition:

wherein, in formula (1) and formula (2), R¹ and R² are independentlyalkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenylhaving 2 to 12 carbons, alkenyloxy having 2 to 12 carbons, or alkylhaving 1 to 12 carbons in which at least one piece of hydrogen isreplaced by fluorine or chlorine; R³ and R⁴ are independently alkylhaving 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2to 12 carbons, alkyl having 1 to 12 carbons in which at least one pieceof hydrogen is replaced by fluorine or chlorine, or alkenyl having 2 to12 carbons in which at least one piece of hydrogen is replaced byfluorine or chlorine; ring A and ring C are independently1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl,1,4-phenylene, 1,4-phenylene in which at least one piece of hydrogen isreplaced by fluorine or chlorine, naphthalene-2,6-diyl,naphthalene-2,6-diyl in which at least one piece of hydrogen is replacedby fluorine or chlorine, chroman-2,6-diyl, chroman-2,6-diyl in which atleast one piece of hydrogen is replaced by fluorine or chlorine, or adivalent group represented by formula (pr-1) or (pr-2);

in which, at least one of ring A and ring C is a ring represented byformula (pr-1) or (pr-2); ring B is 2,3-difluoro-1,4-phenylene,2-chloro-3-fluoro-1,4-phenylene 2,3-difluoro-5-methyl-1,4-phenylene,3,4,5-trifluoronaphthalene-2,6-diyl or 7,8-difluorochroman-2,6-diyl; Z¹and Z² are independently a single bond, ethylene, carbonyloxy ormethyleneoxy; a is 1, 2 or 3; b is 0 or 1; and a sum of a and b is 3 orless.

One advantage of the invention is to provide a liquid crystalcomposition satisfying at least one of characteristics including a highmaximum temperature of a nematic phase, a low minimum temperature of thenematic phase, small viscosity, suitable optical anisotropy, largenegative dielectric anisotropy, large specific resistance, highstability to ultraviolet light and high stability to heat. Anotheradvantage is to provide a liquid crystal composition having a suitablebalance regarding at least two of the above characteristics. Anotheradvantage is to provide a liquid crystal display device including thecomposition. Another advantage is to provide an AM device havingcharacteristics including a short response time, a high voltage holdingratio, a low threshold voltage, a large contrast ratio and a longservice life.

DESCRIPTION OF EMBODIMENTS

Usage of terms herein is as described below. Terms “liquid crystalcomposition” and “liquid crystal display device” may be occasionallyabbreviated as “composition” and “device,” respectively. “Liquid crystaldisplay device” is a generic term for a liquid crystal display panel anda liquid crystal display module. “Liquid crystal compound” is a genericterm for a compound having a liquid crystal phase such as a nematicphase and a smectic phase, and a compound having no liquid crystal phasebut being mixed with the composition for the purpose of adjustingcharacteristics such as a temperature range of the nematic phase,viscosity and dielectric anisotropy. The compound has a six-memberedring such as 1,4-cyclohexylene and 1,4-phenylene, and has rod-likemolecular structure. “Polymerizable compound” includes a compound to beadded to the composition for the purpose of forming a polymer in thecomposition. A liquid crystal compound having alkenyl is notpolymerizable in the above meaning.

The liquid crystal composition is prepared by mixing a plurality ofliquid crystal compounds. An additive such as an optically activecompound, an antioxidant, an ultraviolet light absorber, a dye, anantifoaming agent, a polymerizable compound, a polymerization initiator,a polymerization inhibitor and a polar compound is added to the liquidcrystal composition, when necessary. A proportion of the liquid crystalcompounds is expressed in terms of weight percent (% by weight) based onthe weight of the liquid crystal composition containing no additive,even after the additive has been added. A proportion of the additive isexpressed in terms of weight percent (% by weight) based on the weightof the liquid crystal composition containing no additive. Morespecifically, a proportion of the liquid crystal compound or theadditive is calculated based on the total weight of the liquid crystalcompound. Weight parts per million (ppm) may be occasionally used. Aproportion of the polymerization initiator and the polymerizationinhibitor is exceptionally expressed based on the weight of thepolymerizable compound.

“Maximum temperature of the nematic phase” may be occasionallyabbreviated as “maximum temperature.” “Minimum temperature of thenematic phase” may be occasionally abbreviated as “minimum temperature.”An expression “having large specific resistance” means that thecomposition has large specific resistance in an initial stage, and thecomposition has the large specific resistance after the device has beenused for a long period of time. An expression “having a large voltageholding ratio” means that the composition has a large voltage holdingratio at room temperature and also at a temperature close to the maximumtemperature in an initial stage, and the composition has the largevoltage holding ratio at room temperature and also at a temperatureclose to the maximum temperature even after the device has been used fora long period of time. In the composition or the device, thecharacteristics may be occasionally examined before and after an agingtest (including an acceleration deterioration test). An expression“increase the dielectric anisotropy” means that a value of dielectricanisotropy positively increases in a liquid crystal composition havingpositive dielectric anisotropy, and the value of dielectric anisotropynegatively increases in a liquid crystal composition having a negativedielectric anisotropy.

A compound represented by formula (1) may be occasionally abbreviated as“compound (1).” At least one compound selected from the group ofcompounds represented by formula (1) may be occasionally abbreviated as“compound (1).” “Compound (1)” means one compound, a mixture of twocompounds or a mixture of three or more compounds represented by formula(1). A same rule applies also to any other compound represented by anyother formula. An expression “at least one piece of ‘A’” means that thenumber of ‘A’ is arbitrary. An expression “at least one of ‘A’ may bereplaced by ‘B’” means that when the number of ‘A’ is 1, a position of‘A’ is arbitrary, and when the number of ‘A’ is 2 or more, positionsthereof can be selected without restriction. A same rule applies also toan expression “at least one piece of ‘A’ is replaced by ‘B’.”

An expression “at least one piece of —CH₂— may be replaced by —O—” isused herein. In the above case, —CH₂—CH₂—CH₂— may be converted into—O—CH₂—O— by replacement of non-adjacent —CH₂— by —O—. However, a casewhere —CH₂— adjacent to each other is replaced by —O— is excluded. Thereason is that —O—O—CH₂— (peroxide) is formed in the above replacement.More specifically, the above expression means both “one piece of —CH₂—may be replaced by —O—” and “at least two pieces of non-adjacent —CH₂—may be replaced by —O—.” A same rule applies to replacement to —O—, andalso replacement to a divalent group such as —CH═CH— or —COO—.

A symbol of terminal group R¹ is used in a plurality of compounds inchemical formulas of component compounds. In the compounds, two groupsrepresented by two pieces of arbitrary R¹ may be identical or different.In one case, for example, R¹ of compound (1-1) is ethyl and R¹ ofcompound (1-2) is ethyl. In another case, R¹ of compound (1-1) is ethyland R¹ of compound (1-2) is propyl. A same rule applies also to a symbolsuch as any other terminal group. In formula (3), when a subscript ‘d’is 2, two of rings D exist. In the compound, two rings represented bytwo of rings D may be identical or different. A same rule applies alsoto two of arbitrary rings D where the subscript ‘d’ is larger than 2. Asame rule applies also symbols such as Z⁴ and ring F. A same ruleapplies also to a case of two pieces of -Sp²-P⁵ in compound (5-27).

Symbols such as A, B, C and D surrounded by a hexagonal shape correspondto rings such as ring A, ring B, ring C and ring D, respectively, andrepresent rings such as a six-membered ring and a condensed ring. Incompound (5), an oblique line crossing one side of the hexagonal shaperepresents that arbitrary hydrogen on the ring may be replaced by agroup such as -Sp¹-P¹. A subscript such as ‘h’ represents the number ofgroups to be replaced. When the subscript ‘h’ is 0 (zero), no suchreplacement exists. When the subscript ‘h’ is 2 or more, a plurality ofpieces of -Sp¹-P¹ exist on ring K. The plurality of groups representedby -Sp¹-P¹ may be identical or different. In the expression “ring A andring B are independently X, Y or Z,” the subject is plural, andtherefore “independently” is used. When the subject is “ring A,” thesubject is singular, and therefore “independently” is not used.

Then, 2-fluoro-1,4-phenylene means two divalent groups described below.In a chemical formula, fluorine may be leftward (L) or rightward (R). Asame rule applies also to a left-right asymmetrical divalent groupformed by removing two pieces of hydrogen from a ring, such astetrahydropyran-2,5-diyl. A same rule applies also to a divalent bondinggroup such as carbonyloxy (—COO or —OCO—).

Alkyl of the liquid crystal compound is straight-chain alkyl orbranched-chain alkyl, and includes no cyclic alkyl. Straight-chain alkylis preferred to branched-chain alkyl. A same rule applies also to aterminal group such as alkoxy and alkenyl. With regard to theconfiguration of 1,4-cyclohexylene, trans is preferred to cis forincreasing the maximum temperature.

The invention includes items described below.

Item 1. A liquid crystal composition that has negative dielectricanisotropy, and contains at least one compound selected from the groupof compounds represented by formula (1) as a first component, and atleast one compound selected from the group of compounds represented byformula (2) as a second component:

wherein, in formula (1) and formula (2), R¹ and R² are independentlyalkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenylhaving 2 to 12 carbons, alkenyloxy having 2 to 12 carbons, or alkylhaving 1 to 12 carbons in which at least one piece of hydrogen isreplaced by fluorine or chlorine; R³ and R⁴ are independently alkylhaving 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2to 12 carbons, alkyl having 1 to 12 carbons in which at least one pieceof hydrogen is replaced by fluorine or chlorine, or alkenyl having 2 to12 carbons in which at least one piece of hydrogen is replaced byfluorine or chlorine; ring A and ring C are independently1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl,1,4-phenylene, 1,4-phenylene in which at least one piece of hydrogen isreplaced by fluorine or chlorine, naphthalene-2,6-diyl,naphthalene-2,6-diyl in which at least one piece of hydrogen is replacedby fluorine or chlorine, chroman-2,6-diyl, chroman-2,6-diyl in which atleast one piece of hydrogen is replaced by fluorine or chlorine, or adivalent group represented by formula (pr-1) or (pr-2);

in which, at least one of ring A and ring C is a ring represented byformula (pr-1) or (pr-2); ring B is 2,3-difluoro-1,4-phenylene,2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene,3,4,5-trifluoronaphthalene-2,6-diyl or 7,8-difluorochroman-2,6-diyl; Z¹and Z² are independently a single bond, ethylene, carbonyloxy ormethyleneoxy; a is 1, 2 or 3; b is 0 or 1; and a sum of a and b is 3 orless.

Item 2. The liquid crystal composition according to item 1, containingat least one compound selected from the group of compounds representedby formula (1-1) to formula (1-7) as the first component:

wherein, in formula (1-1) to formula (1-7), R¹ and R² are independentlyalkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenylhaving 2 to 12 carbons, alkenyloxy having 2 to 12 carbons, or alkylhaving 1 to 12 carbons in which at least one piece of hydrogen isreplaced by fluorine or chlorine.

Item 3. The liquid crystal composition according to item 1 or 2, whereina proportion of the first component is in the range of about 5% byweight to about 40% by weight, and a proportion of the second componentis in the range of about 10% by weight to about 60% by weight.

Item 4. The liquid crystal composition according to anyone of items 1 to3, containing at least one compound selected from the group of compoundsrepresented by formula (3) as a third component:

wherein, in formula (3), R⁵ and R⁶ are independently alkyl having 1 to12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12carbons, alkyl having 1 to 12 carbons in which one at least one piece ofhydrogen is replaced by fluorine or chlorine, or alkenyl having 2 to 12carbons in which at least one piece of hydrogen is replaced by fluorineor chlorine; ring D and ring E are independently 1,4-cyclohexylene,1,4-phenylene, 2-fluoro-1,4-phenylene or 2,5-difluoro-1,4-phenylene; Z³is a single bond, ethylene or carbonyloxy; d is 1, 2 or 3; and when d is1, ring E is 1,4-phenylene.

Item 5. The liquid crystal composition according to any one of items 1to 4, containing at least one compound selected from the group ofcompounds represented by formula (3-1) to formula (3-12) as the thirdcomponent:

wherein, in formula (3-1) to formula (3-12), R⁵ and R⁶ are independentlyalkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenylhaving 2 to 12 carbons, alkyl having 1 to 12 carbons in which at leastone piece of hydrogen is replaced by fluorine or chlorine, or alkenylhaving 2 to 12 carbons in which at least one piece of hydrogen isreplaced by fluorine or chlorine.

Item 6. The liquid crystal composition according to item 4 or 5, whereina proportion of the third component is in the range of about 3% byweight to about 40% by weight.

Item 7. The liquid crystal composition according to any one of items 1to 6, containing at least one compound selected from the group ofcompounds represented by formula (4) as a fourth component:

wherein, in formula (4), R⁷ and R⁸ are independently alkyl having 1 to12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12carbons, alkenyloxy having 2 to 12 carbons, or alkyl having 1 to 12carbons in which at least one piece of hydrogen is replaced by fluorineor chlorine; ring F and ring I are independently 1,4-cyclohexylene,1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 1,4-phenylene,1,4-phenylene in which at least one piece of hydrogen is replaced byfluorine or chlorine, naphthalene-2,6-diyl,naphthalene-2,6-diyl in whichat least one piece of hydrogen is replaced by fluorine or chlorine,chroman-2,6-diyl, or chroman-2,6-diyl in which at least one piece ofhydrogen is replaced by fluorine or chlorine; ring G is2,3-difluoro-1,4-phenylene, 2-chloro-3-fluoro-1,4-phenylene,2,3-difluoro-5-methyl-1,4-phenylene, 3,4,5-trifluoronaphthalene-2,6-diylor 7,8-difluorochroman-2,6-diyl; Z⁴ and Z⁵ are independently a singlebond, ethylene, carbonyloxy or methyleneoxy; p is 1, 2 or 3; q is 0 or1; and a sum of p and q is 3 or less.

Item 8. The liquid crystal composition according to any one of items 1to 7, containing at least one compound selected from the group ofcompounds represented by formula (4-1) to formula (4-22) as the fourthcomponent:

wherein, in formula (4-1) to formula (4-22), R⁷ and R⁸ are independentlyalkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenylhaving 2 to 12 carbons, alkenyloxy having 2 to 12 carbons, or alkylhaving 1 to 12 carbons in which at least one piece of hydrogen isreplaced by fluorine or chlorine.

Item 9. The liquid crystal composition according to item 7 or 8, whereina proportion of the fourth component is in the range of about 10% byweight to about 70% by weight.

Item 10. The liquid crystal composition according to any one of items 1to 9, containing at least one compound selected from the group ofpolymerizable compounds represented by formula (5) as an additive:

wherein, in formula (5), ring K and ring M are independently cyclohexyl,cyclohexenyl, phenyl, 1-naphthyl, 2-naphthyl, tetrahydropyran-2-yl,1,3-dioxane-2-yl, pyrimidine-2-yl or pyridine-2-yl, and in the rings, atleast one piece of hydrogen may be replaced by fluorine, chlorine, alkylhaving 1 to 12 carbons, alkoxy having 1 to 12 carbons, or alkyl having 1to 12 carbons in which at least one piece of hydrogen is replaced byfluorine or chlorine; ring L is 1,4-cyclohexylene, 1,4-cyclohexenylene,1,4-phenylene, naphthalene-1,2-diyl, naphthalene-1,3-diyl,naphthalene-1,4-diyl, naphthalene-1,5-diyl, naphthalene-1,6-diyl,naphthalene-1,7-diyl, naphthalene-1,8-diyl, naphthalene-2,3-diyl,naphthalene-2,6-diyl, naphthalene-2,7-diyl, tetrahydropyran-2,5-diyl,1,3-dioxane-2,5-diyl, pyrimidine-2,5-diyl or pyridine-2,5-diyl, and inthe rings, at least one piece of hydrogen may be fluorine, chlorine,alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, or alkylhaving 1 to 12 carbons in which at least one piece of hydrogen isreplaced by fluorine or chlorine; Z⁶ and Z⁷ are independently a singlebond or alkylene having 1 to 10 carbons, and in the alkylene, at leastone piece of —CH₂— may be replaced by —O—, —CO—, —COO— or —OCO—, and atleast one piece of —CH₂—CH₂— may be replaced by —CH═CH—, —C(CH₃)═CH—,—CH═C(CH₃)— or —C(CH₃)═C(CH₃)—, and in the groups, at least one piece ofhydrogen may be replaced by fluorine or chlorine; P¹, P² and P³ areindependently a polymerizable group; Sp¹, Sp² and Sp³ are independentlya single bond or alkylene having 1 to 10 carbons, and in the alkylene,at least piece of —CH₂— may be replaced by —O—, —COO—, —OCO— or —OCOO—,and at least one piece of —CH₂—CH₂— may be replaced by —CH═CH— or —C≡C—,and in the groups, at least one piece of hydrogen may be replaced byfluorine or chlorine; g is 0, 1 or 2; h, j and k are independently 0, 1,2, 3 or 4; and a sum of h, j and k is 1 or more.

Item 11. The liquid crystal composition according to item 10, wherein,in formula (5), P¹, P² and P³ are independently a group selected fromthe group of polymerizable groups represented by formula (p-1) toformula (p-5):

wherein, in formula (p-1) to formula (p-5), M¹, M² and M³ areindependently hydrogen, fluorine, alkyl having 1 to 5 carbons, or alkylhaving 1 to 5 carbons in which at least one piece of hydrogen isreplaced by fluorine or chlorine.

Item 12. The liquid crystal composition according to any one of items 1to 11, containing at least one compound selected from the group ofpolymerizable compounds represented by formula (5-1) to formula (5-27)as the additive:

wherein, in formula (5-1) to formula (5-27), P⁴, P⁵ and P⁶ areindependently a group selected from the group of polymerizable groupsrepresented by formula (P-1) to formula (P-3):

wherein, in formula (P-1) to formula (P-3), M¹, M² and M³ areindependently hydrogen, fluorine, alkyl having 1 to 5 carbons, or alkylhaving 1 to 5 carbons in which at least one piece of hydrogen isreplaced by fluorine or chlorine; and in formula (5-1) to formula(5-27), Sp¹, Sp² and Sp³ are independently a single bond or alkylenehaving 1 to 10 carbons, and in the alkylene, at least one piece of —CH₂—may be replaced by —O—, —COO—, —OCO— or —OCOO—, and at least one pieceof —CH₂—CH₂— may be replaced by —CH═CH— or —C≡C—, and in the groups, atleast one piece of hydrogen may be replaced by fluorine or chlorine.

Item 13. The liquid crystal composition according to any one of items 10to 12, wherein a proportion of the additive is in the range of about0.03% by weight to about 10% by weight.

Item 14. A liquid crystal display device, including the liquid crystalcomposition according to any one of items 1 to 13.

Item 15. The liquid crystal display device according to item 14, whereinan operating mode in the liquid crystal display device includes an IPSmode, a VA mode, an FFS mode or an FPA mode, and a driving mode in theliquid crystal display device includes an active matrix mode.

Item 16. A polymer sustained alignment mode liquid crystal displaydevice, wherein the device includes the liquid crystal compositionaccording to any one of items 1 to 13, or a polymerizable compound inthe liquid crystal composition is polymerized.

Item 17. Use of the liquid crystal composition according to any one ofitems 1 to 13 in a liquid crystal display device.

Item 18. Use of the liquid crystal composition according to any one ofitems 1 to 13 in a polymer sustained alignment mode liquid crystaldisplay device.

The invention further includes the following items: (a) the compositionfurther containing at least one of the additives such as the opticallyactive compound, the antioxidant, the ultraviolet light absorber, thedye, the antifoaming agent, the polymerizable compound, thepolymerization initiator, the polymerization inhibitor and the polarcompound; (b) an AM device including the composition; (c) a polymersustained alignment (PSA) mode AM device including the compositionfurther containing the polymerizable compound; (d) a polymer sustainedalignment (PSA) mode AM device including the composition in which thepolymerizable compound in the composition is polymerized; (e) a deviceincluding the composition and having the PC mode, the TN mode, the STNmode, the ECB mode, the OCB mode, the IPS mode, the VA mode, the FFSmode or the FPA mode; (f) a transmissive device including thecomposition; (g) use of the composition as the composition having thenematic phase; and (h) use as an optically active composition by addingthe optically active compound to the composition.

The composition of the invention will be described in the followingorder. First, a constitution of the composition will be described.Second, main characteristics of the component compounds and main effectsof the compounds on the composition will be described. Third, acombination of components in the composition, a preferred proportion ofthe components and the basis thereof will be described. Fourth, apreferred embodiment of the component compounds will be described.Fifth, a preferred component compounds will be described. Sixth, anadditive that may be added to the composition will be described.Seventh, methods for synthesizing the component compounds will bedescribed. Last, an application of the composition will be described.

First, the constitution of the composition will be described. Thecomposition of the invention is classified into composition A andcomposition B. Composition A may further contain any other liquidcrystal compound, an additive or the like in addition to the liquidcrystal compound selected from compound (1), compound (2), compound (3)and compound (4). An expression “any other liquid crystal compound”means a liquid crystal compound different from compound (1), compound(2), compound (3) and compound (4). Such a compound is mixed with thecomposition for the purpose of further adjusting the characteristics.The additive is the optically active compound, the antioxidant, theultraviolet light absorber, the dye, the antifoaming agent, thepolymerizable compound, the polymerization initiator, the polymerizationinhibitor, the polar compound or the like.

Composition B consists essentially of liquid crystal compounds selectedfrom compound (1), compound (2), compound (3) and compound (4). The term“essentially” means that the composition may contain the additive, butcontains no any other liquid crystal compound. Composition B has asmaller number of components than composition A has. Composition B ispreferred to composition A in view of cost reduction. Composition A ispreferred to composition B in view of possibility of further adjustingthe characteristics by mixing any other liquid crystal compound.

Second, the main characteristics of the component compounds and the maineffects of the compounds on the composition will be described. The maincharacteristics of the component compounds are summarized in Table 2 onthe basis of advantageous effects of the invention. In Table 2, a symbolL stands for “large” or “high,” a symbol M stands for “medium” and asymbol S stands for “small” or “low.” Symbols L, M and S represent aclassification based on a qualitative comparison among the componentcompounds, and 0 (zero) means “a value is close to zero.”

TABLE 2 Characteristics of Components Component Component ComponentComponent (1) (2) (3) Component (4) Maximum S to L M S to L S to Ltemperature Viscosity M to L S S to M M to L Optical M to L S S to L Mto L anisotropy Dielectric M to L¹⁾ 0 0 M to L¹⁾ anisotropy Specific L LL L resistance ¹⁾Dielectric anisotropy is negative, and the symbolstands for magnitude of an absolute value.

Upon mixing the component compounds with the composition, the maineffects of the component compounds on the characteristics of thecomposition are as described below. Compound (1) increases thedielectric anisotropy. Compound (2) decreases the viscosity. Compound(3) increases the maximum temperature or decreases the viscosity.Compound (4) increases the dielectric anisotropy and decreases theminimum temperature. Compound (5) is polymerized to give a polymer, andthe polymer shortens the response time in the device and improves imagepersistence.

Third, the combination of components in the composition, the preferredproportion of the components and the basis thereof will be described. Apreferred combination of the components in the composition includes acombination of the first component and the second component, acombination of the first component, the second component and the thirdcomponent, a combination of the first component, the second componentand the fourth component, a combination of the first component, thesecond component and the additive, a combination of the first component,the second component, the third component and the fourth component, acombination of the first component, the second component, the thirdcomponent and the additive, a combination of the first component, thesecond component, the fourth component and the additive, and acombination of the first component, the second component, the thirdcomponent, the fourth component and the additive. A further preferredcombination thereof includes a combination of the first component, thesecond component, the third component and the fourth component, and acombination of the first component, the second component, the thirdcomponent, the fourth component and the additive.

A preferred proportion of the first component is about 5% by weight ormore for increasing the dielectric anisotropy, and about 40% by weightor less for decreasing the minimum temperature. A further preferredproportion is in the range of about 5% by weight to about 35% by weight.A particularly preferred proportion is in the range of about 5% byweight to about 30% by weight.

A preferred proportion of the second component is about 10% by weight ormore for decreasing the viscosity, and about 60% by weight or less forincreasing the dielectric anisotropy. A further preferred proportion isin the range of about 15% by weight to about 55% by weight. Aparticularly preferred proportion is in the range of about 20% by weightto about 50% by weight.

A preferred proportion of the third component is about 3% by weight ormore for decreasing the viscosity, and about 40% by weight or less forincreasing the dielectric anisotropy. A further preferred proportion isin the range of about 5% by weight to about 35% by weight. Aparticularly preferred proportion is in the range of about 10% by weightto about 30% by weight.

A preferred proportion of the fourth component is about 10% by weight ormore for increasing the dielectric anisotropy, and about 70% by weightor less for decreasing the minimum temperature. A further preferredproportion is in the range of about 15% by weight to about 70% byweight. A particularly preferred proportion is in the range of about 20%by weight to about 65% by weight.

The additive is added to the composition for the purpose of adapting thecomposition to the polymer sustained alignment mode device. A preferredratio of the additive is about 0.03% by weight or more for aligning theliquid crystal molecules, and about 10% by weight or less for preventingpoor display in the device. A further preferred proportion is in therange of about 0.1% by weight to about 2% by weight. A particularlypreferred proportion is in the range of about 0.2% by weight to about1.0% by weight.

Fourth, the preferred embodiment of the component compounds will bedescribed. In formula (1), formula (2), formula (3) and formula (4), R¹,R², R⁷ and R⁸ are independently alkyl having 1 to 12 carbons, alkoxyhaving 1 to 12 carbons, alkenyl having 2 to 12 carbons, alkenyloxyhaving 2 to 12 carbons, or alkyl having 1 to 12 carbons in which atleast one piece of hydrogen is replaced by fluorine or chlorine.Preferred R¹, R², R⁷ or R⁸ is alkyl having 1 to 12 carbons forincreasing the stability, and alkoxy having 1 to 12 carbons forincreasing the dielectric anisotropy. R³, R⁴, R⁵ and R⁶ areindependently alkyl having 1 to 12 carbons, alkoxy having 1 to 12carbons, alkenyl having 2 to 12 carbons, alkyl having 1 to 12 carbons inwhich at least one piece of hydrogen is replaced by fluorine orchlorine, or alkenyl having 2 to 12 carbons in which at least one pieceof hydrogen is replaced by fluorine or chlorine. Preferred R³, R⁴, R⁵ orR⁶ is alkenyl having 2 to 12 carbons for decreasing the viscosity, andalkyl having 1 to 12 carbons for increasing the stability.

Preferred alkyl is methyl, ethyl, propyl, butyl, pentyl, hexyl, heptylor octyl. Further preferred alkyl is methyl, ethyl, propyl, butyl orpentyl for decreasing the viscosity.

Preferred alkoxy is methoxy, ethoxy, propoxy, butoxy, pentyloxy,hexyloxy or heptyloxy. Further preferred alkoxy includes methoxy orethoxy for decreasing the viscosity.

Preferred alkenyl is vinyl, 1-propenyl, 2-propenyl, 1-butenyl,2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl,1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl or 5-hexenyl. Furtherpreferred alkenyl is vinyl, 1-propenyl, 3-butenyl or 3-pentenyl fordecreasing the viscosity. A preferred configuration of —CH═CH— in thealkenyl depends on a position of a double bond. Trans is preferred inalkenyl such as 1-propenyl, 1-butenyl, 1-pentenyl, 1-hexenyl, 3-pentenyland 3-hexenyl for decreasing the viscosity, for instance. Cis ispreferred in alkenyl such as 2-butenyl, 2-pentenyl and 2-hexenyl.

Preferred examples of alkyl in which at least one of hydrogen isreplaced by fluorine or chlorine include fluoromethyl, 2-fluoroethyl,3-fluoropropyl, 4-fluorobutyl, 5-fluoropentyl, 6-fluorohexyl,7-fluoroheptyl or 8-fluorooctyl. Further preferred examples include2-fluoroethyl, 3-fluoropropyl, 4-fluorobutyl or 5-fluoropentyl forincreasing the dielectric anisotropy.

Preferred examples of alkenyl in which at least one of hydrogen isreplaced by fluorine or chlorine include 2,2-difluorovinyl,3,3-difluoro-2-propenyl, 4,4-difluoro-3-butenyl, 5,5-difluoro-4-pentenylor 6,6-difluoro-5-hexenyl. Further preferred examples include2,2-difluorovinyl or 4,4-difluoro-3-butenyl for decreasing theviscosity.

Ring A and ring C are independently 1,4-cyclohexylene,1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 1,4-phenylene,1,4-phenylene in which at least one piece of hydrogen is replaced byfluorine or chlorine, naphthalene-2,6-diyl, naphthalene-2,6-diyl inwhich at least one piece of hydrogen is replaced by fluorine orchlorine, chroman-2,6-diyl, chroman-2,6-diyl in which at least one pieceof hydrogen is replaced by fluorine or chlorine or a divalent grouprepresented by formula (pr-1) or (pr-2);

in which, at least one of ring A and ring C is a ring represented byformula (pr-1) or (pr-2). For decreasing the viscosity or for increasingthe maximum temperature, preferred ring A or ring C is1,4-cyclohexylene, and 1,4-phenylene for decreasing the minimumtemperature. With regard to the configuration of 1,4-cyclohexylene,trans is preferred to cis for increasing the maximum temperature.Tetrahydropyran-2,5-diyl includes:

preferably

Ring B and ring G are independently 2,3-difluoro-1,4-phenylene,2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro 5-methyl-1,4-phenylene,3,4,5-trifluoronaphthalene-2,6-diyl or 7,8-difluorochroman-2,6-diyl.Preferred ring B or ring G is 2,3-difluoro-1,4-phenylene for decreasingthe viscosity, 2-chloro-3-fluoro-1,4-phenylene for decreasing theoptical anisotropy, and 7,8-difluorochroman-2,6-diyl for increasing thedielectric anisotropy.

Ring D and ring E are independently 1,4-cyclohexylene, 1,4-phenylene,2-fluoro-1,4-phenylene, or 2,5-difluoro-1,4-phenylene. Ring E is1,4-phenylene when ring D is one ring. For decreasing the viscosity orfor increasing the maximum temperature, preferred ring D or ring E is1,4-cyclohexylene, and 1,4-phenylene for decreasing the minimumtemperature.

Ring F and ring I are independently 1,4-cyclohexylene,1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 1,4-phenylene,1,4-phenylene in which at least one piece of hydrogen is replaced byfluorine or chlorine, naphthalene-2,6-diyl, naphthalene-2,6-diyl inwhich at least one piece of hydrogen is replaced by fluorine orchlorine, chroman-2,6-diyl, or chroman-2,6-diyl in which at least one ofhydrogen is replaced by fluorine or chlorine. Preferred ring F or ring Iis 2,3-difluoro-1,4-phenylene for decreasing the viscosity,2-chloro-3-fluoro-1,4-phenylene for decreasing the optical anisotropy,and 7,8-difluorochroman-2,6-diyl for increasing the dielectricanisotropy.

Z¹, Z², Z⁴ and Z⁵ are independently a single bond, ethylene, carbonyloxyor methyleneoxy. Preferred Z¹, Z², Z⁴ or Z⁵ is a single bond fordecreasing the viscosity, ethylene for decreasing the minimumtemperature, and methyleneoxy for increasing the dielectric anisotropy.Z³ is a single bond, ethylene or carbonyloxy. Preferred Z³ is a singlebond for increasing the stability.

Then, a is 1, 2 or 3; b is 0 or 1; and a sum of a and b is 3 or less.Preferred a is 1 for decreasing the viscosity, and is 2 or 3 forincreasing the maximum temperature. Preferred b is 0 for decreasing theviscosity, and 1 for decreasing the minimum temperature. d is 1, 2 or 3.Preferred d is 1 for decreasing the viscosity, and 2 or 3 for increasingthe maximum temperature. Then, p is 1, 2 or 3, q is 0 or 1, and a sum ofp and q is 3 or less. Preferred p is 1 for decreasing the viscosity, and2 or 3 for increasing the maximum temperature. Preferred q is 0 fordecreasing the viscosity, and 1 for decreasing the minimum temperature.

In formula (5), P¹, P² and P³ are independently a polymerizable group.Preferred P¹, P² or P³ is a group selected from the group ofpolymerizable groups represented by formula (P-1) to formula (P-5).Further preferred P¹, P² or P³ is the group represented by formula(P-1), formula (P-2) or formula (P-3). Particularly preferred P¹, P² orP³ is the group represented by formula (P-1) or formula (P-2). Mostpreferred P¹, P² or P³ is the group represented by formula (P-1). Apreferred group represented by formula (P-1) is —OCO—CH═CH₂ or—OCO—C(CH₃)═CH₂. A wavy line in formula (P-1) to formula (P-5) shows asite to be bonded.

In formula (P-1) to formula (P-5), M¹, M² and M³ are independentlyhydrogen, fluorine, alkyl having 1 to 5 carbons, or alkyl having 1 to 5carbons in which at least one piece of hydrogen is replaced by fluorineor chlorine. Preferred M¹, M² or M³ is hydrogen or methyl for increasingreactivity. Further preferred M¹ is hydrogen or methyl, and furtherpreferred M² or M³ is hydrogen.

Sp¹, Sp² and Sp³ are independently a single bond or alkylene having 1 to10 carbons, and in the alkylene, at least one piece of —CH₂— may bereplaced by —O—, —COO—, —OCO— or —OCOO—, and at least one piece of—CH₂—CH₂— may be replaced by —CH═CH— or —C≡C—, and in the groups, atleast one piece of hydrogen may be replaced by fluorine or chlorine.Preferred Sp¹, Sp² or Sp³ is a single bond, —CH₂—CH₂—, —CH₂O—, —OCH₂—,—COO—, —OCO—, —CO—CH═CH— or —CH═CH—CO—. Further preferred Sp¹, Sp² orSp³ is a single bond.

Ring K and ring M are independently cyclohexyl, cyclohexenyl, phenyl,1-naphthyl, 2-naphthyl, tetrahydropyran-2-yl, 1,3-dioxane-2-yl,pyrimidine-2-yl or pyridine-2-yl, and in the rings, at least one pieceof hydrogen may be replaced by fluorine, chlorine, alkyl having 1 to 12carbons, alkoxy having 1 to 12 carbons, or alkyl having 1 to 12 carbonsin which one piece of hydrogen is replaced by fluorine or chlorine.Preferred ring K or ring M is phenyl. Ring L is 1,4-cyclohexylene,1,4-cyclohexenylene, 1,4-phenylene, naphthalene-1,2-diyl,naphthalene-1,3-diyl, naphthalene-1,4-diyl, naphthalene-1,5-diyl,naphthalene-1,6-diyl, naphthalene-1,7-diyl, naphthalene-1,8-diyl,naphthalene-2,3-diyl, naphthalene-2,6-diyl, naphthalene-2,7-diyl,tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, pyrimidine-2,5-diyl orpyridine-2,5-diyl, and in the rings, at least one piece of hydrogen maybe replaced by fluorine, chlorine, alkyl having 1 to 12 carbons, alkoxyhaving 1 to 12 carbons, or alkyl having 1 to 12 carbons in which atleast one piece of hydrogen may be replaced by fluorine or chlorine.Preferred ring L is 1,4-phenylene or 2-fluoro-1,4-phenylene.

Z⁶ and Z⁷ are independently a single bond or alkylene having 1 to 10carbons, and in the alkylene, at least one piece of —CH₂— may bereplaced by —O—, —CO—, —COO— or —OCO—, and at least one piece of—CH₂—CH₂— may be replaced by —CH═CH—, —C(CH₃)═CH—, —CH═C(CH₂)— or—C(CH₂)═C(CH₂)—, and in the groups, at least one piece of hydrogen maybe replaced by fluorine or chlorine. Preferred Z⁶ or Z⁷ is a singlebond, —CH₂CH₂—, —CH₂O—, —OCH₂—, —COO— or —OCO—. Further preferred Z⁶ orZ⁷ is a single bond.

Then, g is 0, 1 or 2. Preferred g is 0 or 1. Then, h, j and k areindependently 0, 1, 2, 3 or 4, and a sum of h, j and k is 1 or more.Preferred h, j or k is 1 or 2.

Fifth, the preferred component compounds will be described. Preferredcompound (1) includes compound (1-1) to compound (1-7) described in item2. In the compounds, at least one of the first components preferablyincludes compound (1-1), compound (1-3), compound (1-4) or compound(1-6). At least two of the first components preferably include acombination of compound (1-1) and compound (1-4), a combination ofcompound (1-1) and compound (1-6), a combination of compound (1-1) andcompound (1-7), a combination of compound (1-3) and compound (1-4), acombination of compound (1-3) and compound (1-6) or a combination ofcompound (1-3) and compound (1-7).

Preferred compound (3) includes compound (3-1) to compound (3-12)described in item 5. In the compounds, at least one of the thirdcomponents preferably includes compound (3-2), compound (3-4), compound(3-5) or compound (3-6). At least two of the third components preferablyinclude a combination of compound (3-2) and compound (3-4) or acombination of compound (3-2) and compound (3-6).

Preferred compound (4) includes compound (4-1) to compound (4-22)described in item 8. In the compounds, at least one of the fourthcomponents preferably includes compound (4-1), compound (4-2), compound(4-3), compound (4-4), compound (4-6), compound (4-7), compound (4-8) orcompound (4-10). At least two of the fourth components preferablyinclude a combination of compound (4-1) and compound (4-6), acombination of compound (4-1) and compound (4-10), a combination ofcompound (4-3) and compound (4-6), a combination of compound (4-3) andcompound (4-10), a combination of compound (4-4) and compound (4-6) or acombination of compound (4-4) and compound (4-10).

Preferred compound (5) includes compound (5-1) to compound (5-27)described in item 12. In the compounds, at least one of the additivespreferably includes compound (5-1), compound (5-2), compound (5-24),compound (5-25), compound (5-26) or compound (5-27). At least two of theadditives preferably include a combination of compound (5-1) andcompound (5-2), a combination of compound (5-1) and compound (5-18), acombination of compound (5-2) and compound (5-24), a combination ofcompound (5-2) and compound (5-26), a combination of compound (5-25) andcompound (5-26) or a combination of compound (5-18) and compound (5-24).

Sixth, the additive that may be added to the composition will bedescribed. Such an additive is the optically active compound, theantioxidant, the ultraviolet light absorber, the dye, the antifoamingagent, the polymerizable compound, the polymerization initiator, thepolymerization inhibitor, the polar compound or the like. The opticallyactive compound is added to the composition for the purpose of inducinga helical structure in the liquid crystal molecule to give a twistangle. Examples of such a compound include compound (6-1) to compound(6-5). A preferred proportion of the optically active compound is about5% by weight or less. A further preferred proportion is in the range ofabout 0.01% by weight to about 2% by weight.

The antioxidant is added to the composition for preventing a decrease inthe specific resistance caused by heating in air, or for maintaining alarge voltage holding ratio at room temperature and also at thetemperature close to the maximum temperature even after the device hasbeen used for a long period of time. Preferred examples of theantioxidant include compound (7) where n is an integer from 1 to 9.

In compound (7), preferred n is 1, 3, 5, 7 or 9. Further preferred n is7. Compound (7) where n is 7 is effective in maintaining a large voltageholding ratio at room temperature and also at a temperature close to themaximum temperature even after the device has been used for a longperiod of time because such compound (7) has a small volatility. Apreferred proportion of the antioxidant is about 50 ppm or more forachieving an effect thereof, and about 600 ppm or less for avoiding adecrease in the maximum temperature or an increase in the minimumtemperature. A further preferred proportion is in the range of about 100ppm to about 300 ppm.

Preferred examples of the ultraviolet light absorber include abenzophenone derivative, a benzoate derivative and a triazolederivative. A light stabilizer such as an amine having steric hindranceis also preferred. A preferred proportion of the absorber or thestabilizer is about 50 ppm or more for achieving an effect thereof, andabout 10,000 ppm or less for avoiding the decrease in the maximumtemperature or avoiding the increase in the minimum temperature. Afurther preferred proportion is in the range of about 100 ppm to about10,000 ppm.

A dichroic dye such as an azo dye or an anthraquinone dye is added tothe composition to be adapted for a device having a guest host (GH)mode. A preferred proportion of the dye is in the range of about 0.01%by weight to about 10% by weight. The antifoaming agent such as dimethylsilicone oil or methyl phenyl silicone oil is added to the compositionfor preventing foam formation. A preferred proportion of the antifoamingagent is about 1 ppm or more for achieving an effect thereof, and about1,000 ppm or less for preventing a poor display. A further preferredproportion is in the range of about 1 ppm to about 500 ppm.

The polymerizable compound is used to be adapted for a polymer sustainedalignment (PSA) mode device. Compound (5) is suitable for the purpose.Any other polymerizable compound that is different from compound (5) maybe added to the composition together with compound (5). In place ofcompound (5), any other polymerizable compound that is different fromcompound (5) may be added to the composition. Preferred examples of sucha polymerizable compound include a compound such as acrylate,methacrylate, a vinyl compound, a vinyloxy compound, propenyl ether, anepoxy compound (oxirane, oxetane) and vinyl ketone compound. Furtherpreferred examples include an acrylate derivative or a methacrylatederivative. The reactivity of polymerization and a pretilt angle of theliquid crystal molecule can be adjusted by changing a kind of compound(5), or by combining a polymerizable compound different from compound(5) with compound (5) at a suitable ratio. The short response time ofthe device can be achieved by optimizing the pretilt angle. Alignment ofthe liquid crystal molecule is also stabilized, and therefore a largecontrast ratio and a long service life can be achieved.

The polymerizable compound is polymerized by irradiation withultraviolet light. The polymerizable compound may be polymerized in thepresence of the polymerization initiator such as the photopolymerizationinitiator. A suitable condition for polymerization and a suitable typeand amount of the polymerization initiator are known by those skilled inthe art, and are described in literature. For example, Irgacure 651(registered trademark; BASF), Irgacure 184 (registered trademark; BASF)or Darocur 1173 (registered trademark; BASF), each being aphotoinitiator, is suitable for radical polymerization. A preferredproportion of the photopolymerization initiator is in the range of about0.1% by weight to about 5% by weight based on the weight of thepolymerizable compound. A further preferred proportion is in the rangeof about 1% by weight to about 3% by weight based thereon.

Upon storing the polymerizable compound, the polymerization inhibitormay be added thereto for preventing polymerization. The polymerizablecompound is ordinarily added to the composition without removing thepolymerization inhibitor. Examples of the polymerization inhibitorinclude a hydroquinone derivative such as hydroquinone andmethylhydroquinone; 4-t-butyl-catechol; 4-methoxyphenol andphenothiazine.

The polar compound is an organic compound having polarity. Herein, acompound having an ionic bond is not contained. An atom such as oxygen,sulfur and nitrogen is electrically more negative, and tends to have apartial negative charge. Carbon and hydrogen are neutral or tend to havea partial positive charge. The polarity is formed when the partialpositive charge is not uniformly distributed between different kinds ofatoms in the compound. For example, the polar compound has at least oneof partial structures such as —OH, —COOH, —SH, —NH₂, >NH and >N—.

Seventh, the methods for synthesizing the component compounds will bedescribed. The compounds can be prepared according to known methods.Examples of the synthetic methods are described. Compound (1-1) isprepared by the method described in JP 2011-136914 A. Compound (2) isprepared by the method described in JP S59-176221 A. Compound (3-1) isprepared by the method described in JP S56-68636 A. Compound (4-1) isprepared by the method described in JP H2-503441 A. Compound (5-18) isprepared by the method described in JP H7-101900 A. The antioxidant iscommercially available. A compound represented by formula (7) where n is1 is available from Sigma-Aldrich Corporation. Compound (7) where n is 7and so forth are prepared according to the method described in U.S. Pat.No. 3,660,505 B.

Any compounds whose synthetic methods are not described above can beprepared according to the methods described in books such as OrganicSyntheses (John Wiley & Sons, Inc.), Organic Reactions (John Wiley &Sons, Inc.), Comprehensive Organic Synthesis (Pergamon Press) and NewExperimental Chemistry Course (Shin Jikken Kagaku Koza in Japanese)(Maruzen Co., Ltd.). The composition is prepared according to publiclyknown methods using the compounds thus obtained. For example, thecomponent compounds are mixed and dissolved in each other by heating.

Last, the application of the composition will be described. Most of thecomposition has a minimum temperature of about −10° C. or lower, amaximum temperature of about 70° C. or higher, and an optical anisotropyin the range of about 0.07 to about 0.20. The composition having anoptical anisotropy in the range of about 0.08 to about 0.25 may beprepared by controlling the ratio of the component compounds or bymixing any other liquid crystal compound. Further, the compositionhaving the optical anisotropy in the range of about 0.10 to about 0.30may be prepared by trial and error. A device including the compositionhas the large voltage holding ratio. The composition is suitable for usein the AM device. The composition is particularly suitable for use in atransmissive AM device. The composition can be used as the compositionhaving the nematic phase, and as the optically active composition byadding the optically active compound.

The composition can be used for the AM device. The composition can alsobe used for a PM device. The composition can also be used for an AMdevice and a PM device each having a mode such as the PC mode, the TNmode, the STN mode, the ECB mode, the OCB mode, the IPS mode, the FFSmode, the VA mode and the FPA mode. Use for the AM device having the VAmode, the OCB mode, the IPS mode or the FFS mode is particularlypreferred. In the AM device having the IPS mode or the FFS mode,alignment of liquid crystal molecules when no voltage is applied may beparallel or vertical to a glass substrate. The device may be of areflective type, a transmissive type or a transflective type. Use forthe transmissive device is preferred. The composition can also be usedfor an amorphous silicon-TFT device or a polycrystal silicon-TFT device.The composition can also be used for a nematic curvilinear aligned phase(NCAP) device prepared by microencapsulating the composition, or for apolymer dispersed (PD) device in which a three-dimensionalnetwork-polymer is formed in the composition.

One example of a method of producing the polymer sustained alignmentmode device is as described below. A device having two substratesreferred to as an array substrate and a color filter substrate isassembled. The substrates have an alignment film. At least one of thesubstrates has an electrode layer. The liquid crystal compound is mixedto prepare the liquid crystal composition. The polymerizable compound isadded to the composition. The additive may be further added thereto whennecessary. The composition is injected into the device. The device isirradiated with light while voltage is applied to the device.Ultraviolet light is preferred. The polymerizable compound ispolymerized by light irradiation. The composition containing a polymeris formed by the polymerization. The polymer sustained alignment modedevice is produced by such a procedure.

In the above procedure, when the voltage is applied, the liquid crystalmolecules are aligned by action of the alignment film and an electricfield. The molecules of the polymerizable compound are also alignedaccording to the alignment. The polymerizable compound is polymerized bythe ultraviolet light in the above state, and therefore the polymermaintaining the alignment is formed. The response time of the device isshortened by an effect of the polymer. Simultaneously, image persistenceis also improved by the effect of the polymer, since the imagepersistence is operation failure of the liquid crystal molecule.Moreover, the polymerizable compound in the composition is previouslypolymerized, and the resulting composition can be arranged between thesubstrates of the liquid crystal display device.

EXAMPLES

The invention will be described in greater detail by way of Examples.The invention is not limited by the Examples. The invention includes amixture of a composition in Example 1 and a composition in Example 2.The invention also includes a mixture in which at least two of thecompositions in Examples are mixed. The thus prepared compound wasidentified by methods such as an NMR analysis. Characteristics of thecompound, the composition and a device were measured by methodsdescribed below.

NMR analysis: For measurement, DRX-500 made by Bruker BioSpinCorporation was used. In ¹H-NMR measurement, a sample was dissolved in adeuterated solvent such as CDCl₃, and measurement was carried out underconditions of room temperature, 500 MHz and times of accumulation.Tetramethylsilane was used as an internal standard. In ¹⁹F-NMRmeasurement, CFCl₃ was used as an internal standard, and measurement wascarried out under conditions of 24 times of accumulation. In explainingnuclear magnetic resonance spectra obtained, s, d, t, q, quin, sex and mstand for a singlet, a doublet, a triplet, a quartet, a quintet, asextet and a multiplet, and br being broad, respectively.

Gas chromatographic analysis: For measurement, GC-14B Gas Chromatographmade by Shimadzu Corporation was used. A carrier gas was helium (2 mLper minute). A sample vaporizing chamber and a detector (FID) were setto 280° C. and 300° C., respectively. A capillary column DB-1 (length 30m, bore 0.32 mm, film thickness 0.25 μm; dimethylpolysiloxane as astationary phase, non-polar) made by Agilent Technologies, Inc. was usedfor separation of component compounds. After the column was kept at 200°C. for 2 minutes, the column was heated to 280° C. at a rate of 5° C.per minute. A sample was prepared in an acetone solution (0.1% byweight), and then 1 microliter of the solution was injected into thesample vaporizing chamber. A recorder was C-R5A Chromatopac made byShimadzu Corporation or the equivalent thereof. The resulting gaschromatogram showed a retention time of a peak and a peak areacorresponding to each of the component compounds.

As a solvent for diluting the sample, chloroform, hexane or the like mayalso be used. The following capillary columns may also be used forseparating component compounds: HP-1 (length 30 m, bore 0.32 mm, filmthickness 0.25 μm) made by Agilent Technologies, Inc., Rtx-1 (length 30m, bore 0.32 mm, film thickness 0.25 μm) made by Restek Corporation andBP-1 (length 30 m, bore 0.32 mm, film thickness 0.25 μm) made by SGEInternational Pty. Ltd. A capillary column CBP1-M50-025 (length 50 m,bore 0.25 mm, film thickness 0.25 μm) made by Shimadzu Corporation mayalso be used for the purpose of preventing an overlap of peaks of thecompounds.

A proportion of liquid crystal compounds contained in the compositionmay be calculated by the method as described below. The mixture of theliquid crystal compounds is analyzed by gas chromatography (FID). Anarea ratio of each peak in the gas chromatogram corresponds to the ratio(weight ratio) of the liquid crystal compound. When the capillarycolumns described above were used, a correction coefficient of each ofthe liquid crystal compounds may be regarded as 1 (one). Accordingly,the proportion (% by weight) of the liquid crystal compounds can becalculated from the area ratio of each peak.

Sample for measurement: When characteristics of the composition and thedevice were measured, the composition was used as was as a sample. Uponmeasuring characteristics of a compound, a sample for measurement wasprepared by mixing the compound (15% by weight) with a base liquidcrystal (85% by weight). Values of characteristics of the compound werecalculated, according to an extrapolation method, using values obtainedby measurement. (Extrapolated value)={(measured value of a sample formeasurement)−0.85×(measured value of a base liquid crystal)}/0.15. Whena smectic phase (or crystals) precipitates at the ratio thereof at 25°C., a ratio of the compound to the base liquid crystal was changed stepby step in the order of (10% by weight:90% by weight), (5% by weight:95%by weight) and (1% by weight:99% by weight). Values of maximumtemperature, optical anisotropy, viscosity and dielectric anisotropywith regard to the compound were determined according to theextrapolation method.

A base liquid crystal described below was used. A proportion of thecomponent compound was expressed in terms of weight percent (% byweight).

Measuring method: Physical properties were measured according to themethods described below. Most of the methods are described in theStandard of Japan Electronics and Information Technology IndustriesAssociation (hereinafter, abbreviated as JEITA) discussed andestablished in JEITA (JEITA ED-2521B). A modification of the methods wasalso used. No thin film transistor (TFT) was attached to a TN deviceused for measurement.

(1) Minimum temperature of nematic phase (NI; ° C.): A sample was placedon a hot plate in a melting point apparatus equipped with a polarizingmicroscope, and heated at a rate of 1° C. per minute. Temperature whenpart of the sample began to change from a nematic phase to an isotropicliquid was measured. A maximum temperature of the nematic phase may beoccasionally abbreviated as “maximum temperature.”

(2) Minimum temperature of nematic phase (T_(C); ° C.): Samples eachhaving a nematic phase were put in glass vials and kept in freezers attemperatures of 0° C., −10° C., −20° C., −30° C. and −40° C. for 10days, and then liquid crystal phases were observed. For example, whenthe sample remained in the nematic phase at −20° C. and changed tocrystals or a smectic phase at −30° C., T_(C) of the sample wasexpressed as T_(C)<−20° C. A minimum temperature of the nematic phasemay be occasionally abbreviated as “minimum temperature.”

(3) viscosity (bulk viscosity; η; measured at 20° C.; mPa·s): Formeasurement, an E type rotational viscometer by Tokyo Keiki Co., Ltd.was used.

(4) Viscosity (rotational viscosity; γ1; measured at 25° C.; mPa·s):Measurement was carried out according to the method described in M. Imaiet al., Molecular Crystals and Liquid Crystals, Vol. 259, p. 37 (1995).A sample was put in a VA device in which a distance (cell gap) betweentwo glass substrates was 20 micrometers. Voltage was applied stepwise tothe device in the range of 39 V to 50 V at an increment of 1 V. After aperiod of 0.2 second with no voltage application, voltage was repeatedlyapplied under conditions of only one rectangular wave (rectangularpulse; 0.2 second) and no voltage application (2 seconds). A peakcurrent and a peak time of transient current generated by the appliedvoltage were measured. A value of rotational viscosity was obtained fromthe measured values according to calculating equation (8) on page 40 ofthe paper presented by M. Imai et al. Dielectric anisotropy required forthe calculation was measured according to section (6) described below.

(5) Optical anisotropy (refractive index anisotropy; Δn; measured at 25°C.): Measurement was carried out by an Abbe refractometer with apolarizing plate mounted on an ocular, using light at a wavelength of589 nanometers. A surface of a main prism was rubbed in one direction,and then a sample was added dropwise onto the main prism. A refractiveindex (n∥) was measured when a direction of polarized light was parallelto a direction of rubbing. A refractive index (n⊥) was measured when thedirection of polarized light was perpendicular to the direction ofrubbing. A value of the optical anisotropy was calculated from anequation: Δn=n∥−n⊥.

(6) Dielectric anisotropy (Δε; measured at 25° C.): A value ofdielectric anisotropy was calculated from an equation: Δε=ε∥−ε⊥. Adielectric constant (ε∥ and ε⊥) was measured as described below.

1) Measurement of a dielectric constant (ε∥): An ethanol (20 mL)solution of octadecyltriethoxysilane (0.16 mL) was applied to awell-cleaned glass substrate. After rotating the glass substrate with aspinner, the glass substrate was heated at 150° C. for 1 hour. A samplewas put in a VA device in which a distance (cell gap) between two glasssubstrates was 4 micrometers, and the device was sealed with anultraviolet-curable adhesive. Sine waves (0.5 V, 1 kHz) were applied tothe device, and after 2 seconds, a dielectric constant (ε∥) in a majoraxis direction of the liquid crystal molecules was measured.2) Measurement of a dielectric constant (ε⊥): A polyimide solution wasapplied to a well-cleaned glass substrate. After calcining the glasssubstrate, rubbing treatment was applied to the alignment film obtained.A sample was put in a TN device in which a distance (cell gap) betweentwo glass substrates was 9 micrometers and a twist angle was 80 degrees.Sine waves (0.5 V, 1 kHz) were applied to the device, and after 2seconds, a dielectric constant (ε⊥) in a minor axis direction of theliquid crystal molecules was measured.

(7) Threshold voltage (Vth; measured at 25° C.; V): An LCD-5100luminance meter made by Otsuka Electronics Co., Ltd. was used formeasurement. A light source was a halogen lamp. A sample was put in anormally black mode VA device in which a distance (cell gap) between twoglass substrates was 4 micrometers and a rubbing direction wasanti-parallel, and the device was sealed with an ultraviolet-curableadhesive. A voltage (60 Hz, rectangular waves) to be applied to thedevice was stepwise increased from 0 V to 20 V at an increment of 0.02V. On the occasion, the device was irradiated with light from adirection perpendicular to the device, and an amount of lighttransmitted through the device was measured. A voltage-transmittancecurve was prepared, in which the maximum amount of light corresponds to100% transmittance and the minimum amount of light corresponds to 0%transmittance. A threshold voltage was expressed in terms of voltage at10% transmittance.

(8) Voltage holding ratio (VHR-1; measured at 25° C.; %): A TN deviceused for measurement had a polyimide alignment film, and a distance(cell gap) between two glass substrates was 5 micrometers. A sample wasput in the device, and the device was sealed with an ultraviolet-curableadhesive. A pulse voltage (60 microseconds at 5 V) was applied to the TNdevice and the device was charged. A decaying voltage was measured for16.7 milliseconds with a high-speed voltmeter, and area A between avoltage curve and a horizontal axis in a unit cycle was determined. AreaB is an area without decay. A voltage holding ratio was expressed interms of a percentage of area A to area B.

(9) Voltage holding ratio (VHR-2; measured at 80° C.; %): A voltageholding ratio was measured according to procedures identical with theprocedures described above except that measurement was carried out at80° C. in place of 25° C. The thus obtained value was expressed in termsof VHR-2.

(10) Voltage holding ratio (VHR-3; measured at 25° C.; %): Stability toultraviolet light was evaluated by measuring a voltage holding ratioafter a device was irradiated with ultraviolet light. A TN device usedfor measurement had a polyimide alignment film and a cell gap was 5micrometers. A sample was injected into the device, and then the devicewas irradiated with light for 20 minutes. Alight source was an ultrahigh-pressure mercury lamp USH-500D (made by Ushio, Inc.), and adistance between the device and the light source was 20 centimeters. Inmeasurement of VHR-3, a decaying voltage was measured for 16.7milliseconds. A composition having large VHR-3 has large stability toultraviolet light. A value of VHR-3 is preferably 90% or more, andfurther preferably 95% or more.

(11) Voltage holding ratio (VHR-4; measured at 25° C.; %): Stability toheat was evaluated by measuring a voltage holding ratio after a TNdevice into which a sample was injected was heated in aconstant-temperature bath at 80° C. for 500 hours. In measurement ofVHR-4, a decaying voltage was measured for 16.7 milliseconds. Acomposition having large VHR-4 has large stability to heat.

(12) Response time (τ; measured at 25° C.; ms): An LCD-5100 luminancemeter made by Otsuka Electronics Co., Ltd. was used for measurement. Alight source was a halogen lamp. A low-pass filter was set to 5 kHz. Asample was put in a normally black mode VA device in which a distance(cell gap) between two glass substrates was 4 micrometers and a rubbingdirection was anti-parallel. The device was sealed with anultraviolet-curable adhesive. Voltage (rectangular waves; 60 Hz, 10 V,0.5 second) was applied to the device. On the occasion, the device wasirradiated with light from a direction perpendicular to the device, andan amount of light transmitted through the device was measured. Themaximum amount of light corresponds to 100% transmittance and theminimum amount of light corresponds to 0% transmittance. A response timewas expressed in terms of time required for a change from 90%transmittance to 10% transmittance (fall time; millisecond).

(13) Specific resistance (ρ; measured at 25° C.; Ωcm): Into a vesselequipped with electrodes, 1.0 milliliter of a sample was injected. Adirect current voltage (10 V) was applied to the vessel, and a directcurrent after 10 seconds was measured. Specific resistance wascalculated from the following equation: (specificresistance)={(voltage)×(electric capacity of a vessel)}/{(directcurrent)×(dielectric constant of vacuum)}.

Examples of the composition will be described below. The componentcompounds were expressed using symbols according to definitionsdescribed in Table 3 below. In Table 3, a configuration of1,4-cyclohexylene is trans. Parenthesized numbers described after thesymbolized compounds represent formulas to which the compounds belong. Asymbol (−) means any other liquid crystal compound. A ratio (percentage)of the liquid crystal compound is expressed in terms of weight percent(% by weight) based on the weight of the liquid crystal compositioncontaining no additive. Values of the characteristics of the compositionwere summarized in a last part.

TABLE 3 Method for Description of Compounds using Symbols R—(A₁)—Z₁-. ..-Z_(n)—(A_(n))—R′ 1) Left-terminal Group R— Symbol FC_(n)H_(2n)— Fn-C_(n)H2_(n+1)— n- C_(n)H2_(n+1)O— nO- C_(m)H2_(m+1)OC_(n)H_(2n)— mOn-CH₂═CH— V— C_(n)H_(2n+1)—CH═CH— nV- CH₂═CH—C_(n)H_(2n)— Vn-C_(m)H_(2m+1)—CH═CH—C_(n)H_(2n)— mVn- CF₂═CH— VFF- CF₂═CH—C_(n)H_(2n)—VFFn- C_(m)H_(2m+1)CF₂C_(n)H_(2n)— M(CF₂)n- CH₂═CHCOO— AC-CH₂═C(CH₃)COO— MAC- 2) Right-terminal Group —R′ Symbol —C_(n)H_(2n+1) -n—OC_(n)H_(2n+1) -On —CH═CH₂ —V —CH═CH—C_(n)H_(2n+1) -Vn—C_(n)H_(2n)—CH═CH₂ -nV —C_(m)H_(2m)—CH═CH—C_(n)H_(2n+1) -mVn —CH═CF₂-VFF —OCOCH═CH₂ -AC —OCOC(CH₃)═CH₂ -MAC 3) Bonding Group —Z_(n)— Symbol—C_(n)H_(2n—) n —COO— E —CH═CH— V —CH═CHO— VO —OCH═CH— OV —CH₂O— 1O—OCH₂— O1

ch 4) Ring Structure —A_(n)— Symbol

H

B

B(F)

B(2F)

B(2F,3F)

B(2F,3Cl)

Cro(7F,8F)

dh

Dh

cxO

CxO

Cx 5) Examples of Description Example 1. V-HHB(2F,3F)-O2

Example 2. 2-HCxOB(2F,3F)-O2

Example 3. 3-HBB-1

Example 4. AC-BB-AC

Example 1

3-HCxOB(2F,3F)-O2 (1-4) 5% 5-HCxOB(2F,3F)-O2 (1-4) 5% 3-HH-V (2) 24%1-BB-3 (3-2) 3% 3-HB(2F,3F)-O2 (4-1) 14% 3-BB(2F,3F)-O2 (4-4) 10%2-HHB(2F,3F)-O2 (4-6) 6% 3-HHB(2F,3F)-O2 (4-6) 10% 4-HHB(2F,3F)-O2 (4-6)10% 2-HBB(2F,3F)-O2 (4-10) 3% 3-HHB(2F,3F)-O2 (4-10) 10%

NI=78.7° C.; Tc<−20° C.; η=21.9 mPa·s; Δn=0.108; Δε=−4.5; Vth=1.85 V;γ1=126.1 mPa·s.

Comparative Example 1

The composition in Example 1 contains compound (1) being a firstcomponent. Compound (1) has negative dielectric anisotropy. Forcomparison, a composition in which two compounds being the firstcomponent in Example 1 were replaced by compounds similar thereto wastaken as Comparative Example 1.

3-HCxB(2F,3F)-O2 (—) 5% 5-HCxB(2F,3F)-O2 (—) 5% 3-HH-V (2) 24% 1-BB-3(3-2) 3% 3-HB(2F,3F)-O2 (4-1) 14% 3-BB(2F,3F)-O2 (4-4) 10%2-HHB(2F,3F)-O2 (4-6) 6% 3-HHB(2F,3F)-O2 (4-6) 10% 4-HHB(2F,3F)-O2 (4-6)10% 2-HBB(2F,3F)-O2 (4-10) 3% 3-HBB(2F,3F)-O2 (4-10) 10%

NI=80.9° C.; Δn=0.107; Δε=−3.7; Vth=2.10 V.

Example 2

3-CxOB(2F,3F)-O2 (1-1) 4% 5-CxOB(2F,3F)-O2 (1-1) 4% 3-CxO1OB(2F,3F)-O2(1-3) 4% 3-HCxOB(2F,3F)-O2 (1-4) 4% 5-HCxOB(2F,3F)-O2 (1-4) 4% 3-HH-V(2) 15% 3-HH-V1 (2) 10% 3-HB-O2 (3-1) 3% 3-HHEH-3 (3-3) 5%3-H2B(2F,3F)-O2 (4-2) 3% 5-H2B(2F,3F)-O2 (4-2) 3% 3-BB(2F,3F)-O2 (4-4)10% 3-HHB(2F,3F)-O2 (4-6) 10% 4-HHB(2F,3F)-O2 (4-6) 10% 3-HBB(2F,3F)-O2(4-10) 8% V2-HchB(2F,3F)-O2 (4-19) 3%

NI=76.4° C.; Tc<−20° C.; η=20.2 mPa·s; Δn=0.106; Δε=−4.5; Vth=1.89 V;γ1=120.0 mPa·s.

Example 3

3-HCxOB(2F,3F)-O2 (1-4) 5% 5-HCxOB(2F,3F)-O2 (1-4) 5% 3-HCxO2B(2F,3F)-O2(1-5) 4% 5-HCxO2B(2F,3F)-O2 (1-5) 3% 2-HH-5 (2) 4% 3-HH-4 (2) 3% 3-HH-O1(2) 3% 3-HH-V (2) 10% 3-HH-V1 (2) 7% 3-HB-O2 (3-1) 3% V-HHB-1 (3-4) 3%3-HB(2F,3F)-O2 (4-1) 6% 5-HB(2F,3F)-O2 (4-1) 8% 5-H2B(2F,3F)-O2 (4-2) 3%3-B(2F,3F)B(2F,3F)-O2 (4-5) 3% 2-HHB(2F,3F)-O2 (4-6) 8% 3-HHB(2F,3F)-O2(4-6) 9% 2-HBB(2F,3F)-O2 (4-10) 3% 3-HBB(2F,3F)-O2 (4-10) 10%

NI=82.4° C.; Tc<−20° C.; η=22.1 mPa·s; Δn=0.102; Δε=−4.4; Vth=1.93 V;γ1=131.2 mPa·s.

Example 4

3-CxO1OB(2F, 3F)-O2 (1-3)  3% 5-CxO1OB(2F, 3F)-O2 (1-3)  3% 3-HCxOB(2F,3F)-O2 (1-4)  5% 3-HCxO2B(2F, 3F)-O2 (1-5)  5% 2-HH-3 (2) 16% 3-HH-O1(2)  4% 5-HH-O1 (2)  5% 2-BB(F)B-2V (3-6)  3% 3-HHEBH-3 (3-9)  4%V-HB(2F, 3F)-O2 (4-1)  3% 3-HB(2F, 3F)-O2 (4-1)  5% 3-H1OB(2F, 3F)-O2(4-3)  4% 3-BB(2F, 3F)-O2 (4-4) 10% 3-HHB(2F, 3F)-O2 (4-6) 10% V-HHB(2F,3F)-O2 (4-6)  5% 3-HH1OB(2F, 3F)-O2 (4-8)  5% 3-HBB(2F, 3F)-O2 (4-10)10%

NI=76.8° C.; Tc<−20° C.; η=23.3 mPa·s; Δn=0.105; Δε=−4.8; Vth=1.84 V;γ1=133.3 mPa·s.

Example 5

5-CxOB(2F, 3F)-O2 (1-1)  4% 3-HCxOB(2F, 3F)-O2 (1-4)  5% 5-HCxOB(2F,3F)-O2 ( -4)  3% 3-HCxO1OB(2F, 3F)-O2 (1-6)  4% 5-HCxO1OB(2F, 3F)-O2(1-6)  3% 1V2-HH-2V1 (2)  3% 3-HH-V (2) 15% 3-HH-V1 (2) 12% 1-BB-5 (3-2) 3% 5-B(F)BB-2 (3-7)  3% 3-HB(F)HH-2 (3-8)  2% 3-HB(2F, 3F)-O2 (4-1)  8%2-HHB(2F, 3F)-O2 (4-6)  6% 3-HHB(2F, 3F)-O2 (4-6) 10% 3-HH2B(2F, 3F)-O2(4-7)  3% 3-HBB(2F, 3F)-O2 (4-10)  6% 3-HEB(2F, 3F)B(2F, 3F)-O2 (4-11) 3% 3-HDhB(2F, 3F)-O2 (4-16)  7%

NI=88.4° C.; Tc<−20° C.; η=23.1 mPa·s; Δn=0.106; Δε=−4.3; Vth=1.94 V;γ1=134.2 mPa·s.

Example 6

3-CxOB(2F, 3F)-O2 (1-1)  5% 3-CxO2B(2F, 3F)-O2 (1-2)  3% 3-HCxOB(2F,3F)-O2 (1-4)  5% 5-HCxO1OB(2F, 3F)-O2 (1-6)  3% 3-cxOBB(2F, 3F)-O2 (1-7) 3% 3-HH-V (2) 17% 3-HH-V1 (2) 10% F3-HH-V (2)  3% VFF-HHB-1 (3-4)  3%3-HB(2F, 3F)-O2 (4-1)  7% 3-BB(2F, 3F)-O2 (4-4) 10% 3-HHB(2F, 3F)-O2(4-6) 10% V-HHB(2F, 3F)-O2 (4-6) 10% 4-HBB(2F, 3F)-O2 (4-10)  8%3-HH1OCro(7F, 8F)-5 (4-15)  3%

NI=74.2° C.; Tc<−20° C.; η=20.2 mPa·s; Δn=0.105; Δε=−4.3; Vth=1.91 V;γ1=119.1 mPa·s.

Example 7

5-CxOB(2F, 3F)-O2 (1-1)  5% 3-CxO1OB(2F, 3F)-O2 (1-3)  3% 3-HCxOB(2F,3F)-O2 (1-4)  5% 3-HCxO1OB(2F, 3F)-O2 (1-6)  4% 2-HH-3 (2) 12% 2-HH-5(2) 12% 3-HH-VFF (2)  3% V2-BB-1 (3-2)  3% 3-HHB-O1 (3-4)  3% 3-HB(2F,3F)-O2 (4-1)  9% 5-HB(2F, 3F)-O2 (4-1)  7% 3-HHB(2F, 3F)-O2 (4-6) 10%4-HHB(2F, 3F)-O2 (4-6)  8% 3-HBB(2F, 3F)-O2 (4-10) 11% 3-HBB(2F, 3C1)-O2(4-13)  5%

NI=74.5° C.; Tc<−20° C.; η=23.5 mPa·s; Δn=0.098; Δε=−4.5; Vth=1.88 V;γ1=135.5 mPa·s.

Example 8

3-HCxOB(2F, 3F)-O2 (1-4)  5% 5-HCxOB(2F, 3F)-O2 (1-4)  4% 3-HCxO1OB(2F,3F)-O2 (1-6)  4% 3-HH-V (2) 15% 5-HH-V (2)  8% 3-HH-V1 (2)  5% 1-BB-3(3-2)  3% 5-HBB(F)B-3 (3-12)  3% 3-HB(2F, 3F)-O2 (4-1)  9% 5-HB(2F,3F)-O2 (4-1) 10% V-HHB(2F, 3F)-O2 (4-6) 10% 3-HBB(2F, 3F)-O2 (4-10) 10%5-HBB(2F, 3F)-O2 (4-10)  6% 3-HDhB(2F, 3F)-O2 (4-16)  5% 1O1-HBBH-5 (—) 3%

NI=87.9° C.; Tc<−20° C.; η=22.7 mPa·s; Δn=0.108; Δε=−4.4; Vth=1.94 V;γ1=133.2 mPa·s.

Example 9

3-CxOB(2F, 3F)-O2 (1-1)  5% 3-HCxOB(2F, 3F)-O2 (1-4)  5% 3-HCxO1OB(2F,3F)-O2 (1-6)  3% 5-HCxO1OB(2F, 3F)-O2 (1-6)  4% 2-HH-3 (2) 20% 3-HH-4(2) 10% 1V2-BB-1 (3-2)  3% 5-HB(F)BH-3 (3-11)  3% 3-HB(2F, 3F)-O2 (4-1)13% 5-HH2B(2F, 3F)-O2 (4-7)  4% V-HH1OB(2F, 3F)-O2 (4-8) 10% 4-HBB(2F,3F)-O2 (4-10)  6% 3-HEB(2F, 3F)B(2F, 3F)-O2 (4-11)  3% 3-HHB(2F, 3C1)-O2(4-12)  5% 3-HchB(2F, 3F)-O2 (4-19)  3% 5-HchB(2F, 3F)-O2 (4-19)  3%

NI=76.0° C.; Tc<−20° C.; η=23.8 mPa·s; Δn=0.093; Δε=−4.3; Vth=1.92 V;γ1=135.8 mPa·s.

Example 10

3-CxO2B(2F, 3F)-O2 (1-2)  3% 3-CxO1OB(2F, 3F)-O2 (1-3)  4% 3-HCxOB(2F,3F)-O2 (1-4)  5% 3-HCxO2B(2F, 3F)-O2 (1-5)  5% 3-HH-V (2) 18% 3-HH-V1(2) 12% 5-HB-O2 (3-1)  3% 3-HBB-2 (3-5)  3% 3-HB(2F, 3F)-O2 (4-1)  8%5-HB(2F, 3F)-O2 (4-1)  6% 2O-BB(2F, 3F)-O2 (4-4)  5% 2-HHB(2F, 3F)-O2(4-6)  6% 3-HHB(2F, 3F)-O2 (4-6) 10% 3-HBB(2F, 3F)-O2 (4-10) 12%

NI=76.4° C.; Tc<−20° C.; η=17.9 mPa·s; Δn=0.105; Δε=−4.4; Vth=1.89 V;γ1=105.0 mPa·s.

Example 11

3-CxOB(2F, 3F)-O2 (1-1)  4% 5-CxOB(2F, 3F)-O2 (1-1)  3% 2-HH-3 (2)  9%2-HH-5 (2)  4% 3-HH-4 (2)  5% 3-HH-V1 (2) 10% 7-HB-1 (3-1)  5%2-BB(F)3-3 (3-6)  3% V-HB(2F, 3F)-O2 (4-1)  4% 3-HB(2F, 3F)-O2 (4-1) 10%3-HHB(2F, 3F)-O2 (4-6) 10% V-HHB(2F, 3F)-O2 (4-6) 10% 2-HH1OB(2F, 3F)-O2(4-8)  3% 3-HBB(2F, 3F)-O2 (4-10)  8% 5-HBB(2F, 3F)-O2 (4-10)  7%V-HBB(2F, 3F)-O2 (4-10)  3% 3-chB(2F, 3F)-O2 (4-18)  2%

NI=76.0° C.; Tc<−20° C.; η=20.2 mPa·s; Δn=0.103; Δε=−4.5; Vth=1.88 V;γ1=115.7 mPa·s.

Example 12

3-CxOB(2F, 3F)-O2 (1-1)  3% 5-CxO1OB(2F, 3F)-O2 (1-3)  5% 3-HCxOB(2F,3F)-O2 (1-4)  4% 5-HCxOB(2F, 3F)-O2 (1-4)  3% 3-HH-V (2) 18% 3-HH-V1 (2)13% 1-BB-5 (3-2)  3% 5-HB(2F, 3F)-O2 (4-1) 13% 2-HHB(2F, 3F)-O2 (4-6) 6% 3-HHB(2F, 3F)-O2 (4-6) 10% 4-HHB(2F, 3F)-O2 (4-6)  5% 2-BB(2F,3F)3-3 (4-9)  4% 2-HBB(2F, 3F)-O2 (4-10)  3% 3-HBB(2F, 3F)-O2 (4-10) 10%

NI=78.8° C.; Tc<−20° C.; η=19.2 mPa·s; Δn=0.106; Δε=−4.4; Vth=1.88 V;γ1=113.3 mPa·s.

Example 13

3-CxOB(2F, 3F)-O2 (1-1)  4% 5-CxOB(2F, 3F)-O2 (1-1)  3% 3-HCxOB(2F,3F)-O2 (1-4)  4% 5-HCxOB(2F, 3F)-O2 (1-4)  4% 5-cxOBB(2F, 3F)-O2 (1-7) 3% 3-HH-V (2) 18% 5-HH-V (2)  4% 3-HH-V1 (2)  5% 3-HHB-1 (3-4)  3%3-HB(2F, 3F)-O2 (4-1) 13% 3-BB(2F, 3F)-O2 (4-4) 10% 2-HHB(2F, 3F)-O2(4-6)  6% 3-HHB(2F, 3F)-O2 (4-6) 10% V-HBB(2F, 3F)-O2 (4-10) 10%5-HHB(2F, 3C1)-O2 (4-12)  3%

NI=70.8° C.; Tc<−20° C.; η=20.8 mPa·s; Δn=0.106; Δε=−4.5; Vth=1.84 V;γ1=119.3 mPa·s.

Example 14

3-CxO2B(2F, 3F)-O2 (1-2)  5% 3-HCxOB(2F, 3F)-O2 (1-4)  4% 5-HCxOB(2F,3F)-O2 (1-4)  5% 2-HH-3 (2)  6% 2-HH-5 (2)  7% 3-HH-V (2) 10% 3-HH-V1(2)  5% V-HHB-1 (3-4)  3% V-HBB-3 (3-5)  3% 3-HB(2F, 3F)-O2 (4-1) 10%2-H1OB(2F, 3F)-O2 (4-3)  3% 5-BB(2F, 3F)-O2 (4-4)  5% 3-HH1OB(2F, 3F)-O2(4-8)  5% V-HH1OB(2F, 3F)-O2 (4-8)  3% 3-HBB(2F, 3F)-O2 (4-10)  6%5-HBB(2F, 3F)-O2 (4-10)  6% 3-HEB(2F, 3F)B(2F, 3F)-O2 (4-11)  8%V-chB(2F, 3F)-O2 (4-18)  3% 5-HchB(2F, 3F)-O2 (4-19)  3%

NI=73.9° C.; Tc<−20° C.; η=22.8 mPa·s; Δn=0.106; Δε=−4.6; Vth=1.82 V;γ1=129.5 mPa·s.

Example 15

3-CxO2B(2F, 3F)-O2 (1-2)  3% 3-CxO1OB(2F, 3F)-O2 (1-3)  5% 5-CxO1OB(2F,3F)-O2 (1-3)  5% 3-HCxOB(2F, 3F)-O2 (1-4)  4% 3-HH-V (2) 27% 3-HHEH-5(3-3)  3% 5-HBBH-3 (3-10)  3% 3-HE(2F, 3F)-O2 (4-1) 14% 3-HHB(2F, 3F)-O2(4-6) 10% 4-HHB(2F, 3F)-O2 (4-6) 10% 2-HBB(2F, 3F)-O2 (4-10)  3%3-HBB(2F, 3F)-O2 (4-10) 10% 3-dhBB(2F, 3F)-O2 (4-17)  3%

NI=78.7° C.; Tc<−20° C.; η=21.9 mPa·s; Δn=0.098; Δε=−4.4; Vth=1.90 V;γ1=126.1 mPa·s.

Example 16

5-CxOB(2F, 3F)-O2 (1-1)  3% 3-CxO1O8(2F, 3F)-O2 (1-3)  3% 3-HCxOB(2F,3F)-O2 (1-4)  5% 3-HCxO1OB(2F, 3F)-O2 (1-6)  3% 3-HH-V (2) 25% 3-HH-V1(2)  8% 5-HBB(F)B-2 (3-12)  3% 3-HB(2F, 3F)-O2 (4-1) 10% 5-BB(2F, 3F)-O2(4-4)  5% 3-HHB(2F, 3F)-O2 (4-6) 10% 4-HHB(2F, 3F)-O2 (4-6) 10%3-HBB(2F, 3F)-O2 (4-10)  5% 3-HEB(2F, 3F)B(2F, 3F)-O2 (4-11)  7%5-HBB(2F, 3C1)-O2 (4-13)  3%

NI=82.5° C.; Tc<−20° C.; η=23.3 mPa·s; Δn=0.102; Δε=−4.4; Vth=1.91 V;γ1=133.0 mPa·s.

Example 17

5-CxO2B(2F, 3F)-O2 (1-2)  3% 3-HCxOB(2F, 3F)-O2 (1-4)  3% 5-HCxOB(2F,3F)-O2 (1-4)  3% 3-HCxO1OB(2F, 3F)-O2 (1-6)  3% 5-HCxO1OB(2F, 3F)-O2(1-6)  3% 2-HH-5 (2)  8% 3-HH-4 (2)  8% 3-HH-V1 (2) 13% V2-HHB-1 (3-4) 3% 3-HHEBH-4 (3-9)  3% 3-HB(2F, 3F)-O2 (4-1) 14% 2-HHB(2F, 3F)-O2 (4-6) 6% 3-HHB(2F, 3F)-O2 (4-6) 10% 2-BB(2F, 3F)B-4 (4-9)  3% 3-HBB(2F,3F)-O2 (4-10) 10% 3-HBB(2F, 3C1)-O2 (4-13)  3% 3-H1OCro(7F, 8F)-5 (4-14) 4%

NI=88.5° C.; Tc<−20° C.; η=24.8 mPa·s; Δn=0.102; Δε=−4.3; Vth=1.95 V;γ1=143.6 mPa·s.

Example 18

5-CxOB(2F, 3F)-O2 (1-1)  3% 3-HCxOB(2F, 3F)-O2 (1-4)  4% 3-HCxO1OB(2F,3F)-O2 (1-6)  4% 5-HCxO1OB(2F, 3F)-O2 (1-6)  4% 2-HH-3 (2)  7% 3-HH-O1(2)  3% 3-HH-V (2) 10% 5-HH-V (2) 10% 3-HH-V1 (2) 10% V-HBB-2 (3-5)  3%5-HB(2F, 3F)-O2 (4-1)  5% 2-H1OB(2F, 3F)-O2 (4-3)  5% V-HHB(2F, 3F)-O2(4-6)  5% 2-HH1OB(2F, 3F)-O2 (4-8)  5% 3-HH1OB(2F, 3F)-O2 (4-8)  5%2-BB(2F, 3F)B-3 (4-9)  3% 3-H1OCro(7F, 8F)-5 (4-14)  4% 3-HDhB(2F,3F)-O2 (4-16)  5% 3-HchB(2F, 3F)-O2 (4-19)  5%

NI=73.0° C.; Tc<−20° C.; η=19.9 mPa·s; Δn=0.086; Δε=−4.3; Vth=1.93 V;γ1=114.4 mPa·s.

The dielectric anisotropy (Δε) of the composition in Comparative Example1 was −3.7. On the other hand, the dielectric anisotropy of thecomposition in Example 1 was −4.5. Thus, the compositions in Exampleshad larger negative dielectric anisotropy in comparison with the valuesin Comparative Example. Accordingly, the liquid crystal composition ofthe invention is concluded to have superb characteristics.

INDUSTRIAL APPLICABILITY

A liquid crystal composition according to the invention can be used in aliquid crystal projector, a liquid crystal television or the like.

What is claimed is:
 1. A liquid crystal composition that has negativedielectric anisotropy, and contains at least one compound selected fromthe group of compounds represented by formula (1) as a first component,and at least one compound selected from the group of compoundsrepresented by formula (2) as a second component:

wherein, in formula (1) and formula (2), R¹ and R² are independentlyalkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenylhaving 2 to 12 carbons, alkenyloxy having 2 to 12 carbons, or alkylhaving 1 to 12 carbons in which at least one hydrogen is replaced byfluorine or chlorine; R³ and R⁴ are independently alkyl having 1 to 12carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons,alkyl having 1 to 12 carbons in which at least one hydrogen is replacedby fluorine or chlorine, or alkenyl having 2 to 12 carbons in which atleast one hydrogen is replaced by fluorine or chlorine; ring A and ringC are independently 1,4-cyclohexylene, 1,4-cyclohexenylene,tetrahydropyran-2,5-diyl, 1,4-phenylene, 1,4-phenylene in which at leastone hydrogen is replaced by fluorine or chlorine, naphthalene-2,6-diyl,naphthalene-2,6-diyl in which at least one hydrogen is replaced byfluorine or chlorine, chroman-2,6-diyl, chroman-2,6-diyl in which atleast one hydrogen is replaced by fluorine or chlorine, or a divalentgroup represented by formula (pr-1) or (pr-2);

in which, at least one of ring A and ring C is a ring represented byformula (pr-1) or (pr-2); ring B is 2,3-difluoro-1,4-phenylene,2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene,3,4,5-trifluoronaphthalene-2,6-diyl or 7,8-difluorochroman-2,6-diyl; Z¹and Z² are independently a single bond, ethylene, carbonyloxy ormethyleneoxy; a is 1, 2 or 3; b is 0 or 1; and a sum of a and b is 1, 2or
 3. 2. The liquid crystal composition according to claim 1, containingat least one compound selected from the group of compounds representedby formula (1-1) to formula (1-7) as the first component:

wherein, in formula (1-1) to formula (1-7), R¹ and R² are independentlyalkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenylhaving 2 to 12 carbons, alkenyloxy having 2 to 12 carbons, or alkylhaving 1 to 12 carbons in which at least one hydrogen is replaced byfluorine or chlorine.
 3. The liquid crystal composition according toclaim 1, wherein a proportion of the first component is in the range ofabout 5% by weight to about 40% by weight, and a proportion of thesecond component is in the range of about 10% by weight to about 60% byweight.
 4. The liquid crystal composition according to claim 1,containing at least one compound selected from the group of compoundsrepresented by formula (3) as a third component:

wherein, in formula (3), R⁵ and R⁶ are independently alkyl having 1 to12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12carbons, alkyl having 1 to 12 carbons in which one at least one hydrogenis replaced by fluorine or chlorine, or alkenyl having 2 to 12 carbonsin which at least one hydrogen is replaced by fluorine or chlorine; ringD and ring E are independently 1,4-cyclohexylene, 1,4-phenylene,2-fluoro-1,4-phenylene or 2,5-difluoro-1,4-phenylene; Z³ is a singlebond, ethylene or carbonyloxy; d is 1, 2 or 3; and when d is 1, ring Eis 1,4-phenylene.
 5. The liquid crystal composition according to claim1, containing at least one compound selected from the group of compoundsrepresented by formula (3-1) to formula (3-12) as a third component:

wherein, in formula (3-1) to formula (3-12), R⁵ and R⁶ are independentlyalkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenylhaving 2 to 12 carbons, alkyl having 1 to 12 carbons in which at leastone hydrogen is replaced by fluorine or chlorine, or alkenyl having 2 to12 carbons in which at least one hydrogen is replaced by fluorine orchlorine.
 6. The liquid crystal composition according to claim 4,wherein a proportion of the third component is in the range of about 3%by weight to about 40% by weight.
 7. The liquid crystal compositionaccording to claim 1, containing at least one compound selected from thegroup of compounds represented by formula (4) as an additionalcomponent:

wherein, in formula (4), R⁷ and R⁸ are independently alkyl having 1 to12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12carbons, alkenyloxy having 2 to 12 carbons, or alkyl having 1 to 12carbons in which at least one hydrogen is replaced by fluorine orchlorine; ring F and ring I are independently 1,4-cyclohexylene,1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 1,4-phenylene,1,4-phenylene in which at least one hydrogen is replaced by fluorine orchlorine, naphthalene-2,6-diyl,naphthalene-2,6-diyl in which at leastone hydrogen is replaced by fluorine or chlorine, chroman-2,6-diyl, orchroman-2,6-diyl in which at least one hydrogen is replaced by fluorineor chlorine; ring G is 2,3-difluoro-1,4-phenylene,2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene,3,4,5-trifluoronaphthalene-2,6-diyl or 7,8-difluorochroman-2,6-diyl; Z⁴and Z⁵ are independently a single bond, ethylene, carbonyloxy ormethyleneoxy; p is 1, 2 or 3; q is 0 or 1; and a sum of p and q is 3 orless.
 8. The liquid crystal composition according to claim 4, containingat least one compound selected from the group of compounds representedby formula (4) as an additional component:

wherein, in formula (4), R⁷ and R⁸ are independently alkyl having 1 to12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12carbons, alkenyloxy having 2 to 12 carbons, or alkyl having 1 to 12carbons in which at least one hydrogen is replaced by fluorine orchlorine; ring F and ring I are independently 1,4-cyclohexylene,1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 1,4-phenylene,1,4-phenylene in which at least one hydrogen is replaced by fluorine orchlorine, naphthalene-2,6-diyl,naphthalene-2,6-diyl in which at leastone hydrogen is replaced by fluorine or chlorine, chroman-2,6-diyl, orchroman-2,6-diyl in which at least one hydrogen is replaced by fluorineor chlorine; ring G is 2,3-difluoro-1,4-phenylene,2-chloro-3-fluoro-1,4-phenylene, 2,3-difluoro-5-methyl-1,4-phenylene,3,4,5-trifluoronaphthalene-2,6-diyl or 7,8-difluorochroman-2,6-diyl; Z⁴and Z⁵ are independently a single bond, ethylene, carbonyloxy ormethyleneoxy; p is 1, 2 or 3; q is 0 or 1; and a sum of p and q is 3 orless.
 9. The liquid crystal composition according to claim 1, containingat least one compound selected from the group of compounds representedby formula (4-1) to formula (4-22) as an additional component:

wherein, in formula (4-1) to formula (4-22), R⁷ and R⁸ are independentlyalkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenylhaving 2 to 12 carbons, alkenyloxy having 2 to 12 carbons, or alkylhaving 1 to 12 carbons in which at least one hydrogen is replaced byfluorine or chlorine.
 10. The liquid crystal composition according toclaim 7, wherein a proportion of the additional component is in therange of about 10% by weight to about 70% by weight.
 11. The liquidcrystal composition according to any one of claim 1, containing at leastone compound selected from the group of polymerizable compoundsrepresented by formula (5) as an additive:

wherein, in formula (5), ring K and ring M are independently cyclohexyl,cyclohexenyl, phenyl, 1-naphthyl, 2-naphthyl, tetrahydropyran-2-yl,1,3-dioxane-2-yl, pyrimidine-2-yl or pyridine-2-yl, and in the rings, atleast one hydrogen may be replaced by fluorine, chlorine, alkyl having 1to 12 carbons, alkoxy having 1 to 12 carbons, or alkyl having 1 to 12carbons in which at least one hydrogen is replaced by fluorine orchlorine; ring L is 1,4-cyclohexylene, 1,4-cyclohexenylene,1,4-phenylene, naphthalene-1,2-diyl, naphthalene-1,3-diyl,naphthalene-1,4-diyl, naphthalene-1,5-diyl, naphthalene-1,6-diyl,naphthalene-1,7-diyl, naphthalene-1,8-diyl, naphthalene-2,3-diyl,naphthalene-2,6-diyl, naphthalene-2,7-diyl, tetrahydropyran-2,5-diyl,1,3-dioxane-2,5-diyl, pyrimidine-2,5-diyl or pyridine-2,5-diyl, and inthe rings, at least one hydrogen may be fluorine, chlorine, alkyl having1 to 12 carbons, alkoxy having 1 to 12 carbons, or alkyl having 1 to 12carbons in which at least one hydrogen is replaced by fluorine orchlorine; Z⁶ and Z⁷ are independently a single bond or alkylene having 1to 10 carbons, and in the alkylene, at least one —CH₂— may be replacedby —O—, —CO—, —COO— or —OCO—, and at least one —CH₂—CH₂— may be replacedby —CH═CH—, —C(CH₃)═CH—, —CH═C(CH₃)— or —C(CH₃)═C(CH₃)—, and in thegroups, at least one hydrogen may be replaced by fluorine or chlorine;P¹, P² and P³ are independently a polymerizable group; Sp¹, Sp² and Sp³are independently a single bond or alkylene having 1 to 10 carbons, andin the alkylene, at least one —CH₂— may be replaced by —O—, —COO—, —OCO—or —OCOO—, and at least one —CH₂—CH₂— may be replaced by —CH═CH— or—C≡C—, and in the groups, at least one hydrogen may be replaced byfluorine or chlorine; g is 0, 1 or 2; h, j and k are independently 0, 1,2, 3 or 4; and a sum of h, j and k is 1 or more.
 12. The liquid crystalcomposition according to claim 4, containing at least one compoundselected from the group of polymerizable compounds represented byformula (5) as an additive:

wherein, in formula (5), ring K and ring M are independently cyclohexyl,cyclohexenyl, phenyl, 1-naphthyl, 2-naphthyl, tetrahydropyran-2-yl,1,3-dioxane-2-yl, pyrimidine-2-yl or pyridine-2-yl, and in the rings, atleast one hydrogen may be replaced by fluorine, chlorine, alkyl having 1to 12 carbons, alkoxy having 1 to 12 carbons, or alkyl having 1 to 12carbons in which at least one hydrogen is replaced by fluorine orchlorine; ring L is 1,4-cyclohexylene, 1,4-cyclohexenylene,1,4-phenylene, naphthalene-1,2-diyl, naphthalene-1,3-diyl,naphthalene-1,4-diyl, naphthalene-1,5-diyl, naphthalene-1,6-diyl,naphthalene-1,7-diyl, naphthalene-1,8-diyl, naphthalene-2,3-diyl,naphthalene-2,6-diyl, naphthalene-2,7-diyl, tetrahydropyran-2,5-diyl,1,3-dioxane-2,5-diyl, pyrimidine-2,5-diyl or pyridine-2,5-diyl, and inthe rings, at least one hydrogen may be fluorine, chlorine, alkyl having1 to 12 carbons, alkoxy having 1 to 12 carbons, or alkyl having 1 to 12carbons in which at least one hydrogen is replaced by fluorine orchlorine; Z⁶ and Z⁷ are independently a single bond or alkylene having 1to 10 carbons, and in the alkylene, at least one —CH₂— may be replacedby —O—, —CO—, —COO— or —OCO—, and at least one —CH₂—CH₂— may be replacedby —CH═CH—, —C(CH₃)═CH—, —CH═C(CH₃)— or —C(CH₃)═C(CH₃)—, and in thegroups, at least one hydrogen may be replaced by fluorine or chlorine;P¹, P² and P³ are independently a polymerizable group; Sp¹, Sp² and Sp³are independently a single bond or alkylene having 1 to 10 carbons, andin the alkylene, at least one —CH₂— may be replaced by —O—, —COO—, —OCO—or —OCOO—, and at least one —CH₂—CH₂— may be replaced by —CH═CH— or—C≡C—, and in the groups, at least one hydrogen may be replaced byfluorine or chlorine; g is 0, 1 or 2; h, j and k are independently 0, 1,2, 3 or 4; and a sum of h, j and k is 1 or more.
 13. The liquid crystalcomposition according to claim 7, containing at least one compoundselected from the group of polymerizable compounds represented byformula (5) as an additive:

wherein, in formula (5), ring K and ring M are independently cyclohexyl,cyclohexenyl, phenyl, 1-naphthyl, 2-naphthyl, tetrahydropyran-2-yl,1,3-dioxane-2-yl, pyrimidine-2-yl or pyridine-2-yl, and in the rings, atleast one hydrogen may be replaced by fluorine, chlorine, alkyl having 1to 12 carbons, alkoxy having 1 to 12 carbons, or alkyl having 1 to 12carbons in which at least one hydrogen is replaced by fluorine orchlorine; ring L is 1,4-cyclohexylene, 1,4-cyclohexenylene,1,4-phenylene, naphthalene-1,2-diyl, naphthalene-1,3-diyl,naphthalene-1,4-diyl, naphthalene-1,5-diyl, naphthalene-1,6-diyl,naphthalene-1,7-diyl, naphthalene-1,8-diyl, naphthalene-2,3-diyl,naphthalene-2,6-diyl, naphthalene-2,7-diyl, tetrahydropyran-2,5-diyl,1,3-dioxane-2,5-diyl, pyrimidine-2,5-diyl or pyridine-2,5-diyl, and inthe rings, at least one hydrogen may be fluorine, chlorine, alkyl having1 to 12 carbons, alkoxy having 1 to 12 carbons, or alkyl having 1 to 12carbons in which at least one hydrogen is replaced by fluorine orchlorine; Z⁶ and Z⁷ are independently a single bond or alkylene having 1to 10 carbons, and in the alkylene, at least one —CH₂— may be replacedby —O—, —CO—, —COO— or —OCO—, and at least one —CH₂—CH₂— may be replacedby —CH═CH—, —C(CH₃)═CH—, —CH═C(CH₃)— or —C(CH₃)═C(CH₃)—, and in thegroups, at least one hydrogen may be replaced by fluorine or chlorine;P¹, P² and P³ are independently a polymerizable group; Sp¹, Sp² and Sp³are independently a single bond or alkylene having 1 to 10 carbons, andin the alkylene, at least one —CH₂— may be replaced by —O—, —COO—, —OCO—or —OCOO—, and at least one —CH₂—CH₂— may be replaced by —CH═CH— or—C≡C—, and in the groups, at least one hydrogen may be replaced byfluorine or chlorine; g is 0, 1 or 2; h, j and k are independently 0, 1,2, 3 or 4; and a sum of h, j and k is 1 or more.
 14. The liquid crystalcomposition according to claim 8, containing at least one compoundselected from the group of polymerizable compounds represented byformula (5) as an additive:

wherein, in formula (5), ring K and ring M are independently cyclohexyl,cyclohexenyl, phenyl, 1-naphthyl, 2-naphthyl, tetrahydropyran-2-yl,1,3-dioxane-2-yl, pyrimidine-2-yl or pyridine-2-yl, and in the rings, atleast one hydrogen may be replaced by fluorine, chlorine, alkyl having 1to 12 carbons, alkoxy having 1 to 12 carbons, or alkyl having 1 to 12carbons in which at least one hydrogen is replaced by fluorine orchlorine; ring L is 1,4-cyclohexylene, 1,4-cyclohexenylene,1,4-phenylene, naphthalene-1,2-diyl, naphthalene-1,3-diyl,naphthalene-1,4-diyl, naphthalene-1,5-diyl, naphthalene-1,6-diyl,naphthalene-1,7-diyl, naphthalene-1,8-diyl, naphthalene-2,3-diyl,naphthalene-2,6-diyl, naphthalene-2,7-diyl, tetrahydropyran-2,5-diyl,1,3-dioxane-2,5-diyl, pyrimidine-2,5-diyl or pyridine-2,5-diyl, and inthe rings, at least one hydrogen may be fluorine, chlorine, alkyl having1 to 12 carbons, alkoxy having 1 to 12 carbons, or alkyl having 1 to 12carbons in which at least one hydrogen is replaced by fluorine orchlorine; Z⁶ and Z⁷ are independently a single bond or alkylene having 1to 10 carbons, and in the alkylene, at least one —CH₂— may be replacedby —O—, —CO—, —COO— or —OCO—, and at least one —CH₂—CH₂— may be replacedby —CH═CH—, —C(CH₃)═CH—, —CH═C(CH₃)— or —C(CH₃)═C(CH₃)—, and in thegroups, at least one hydrogen may be replaced by fluorine or chlorine;P¹, P² and P³ are independently a polymerizable group; Sp¹, Sp² and Sp³are independently a single bond or alkylene having 1 to 10 carbons, andin the alkylene, at least one —CH₂— may be replaced by —O—, —COO—, —OCO—or —OCOO—, and at least one —CH₂—CH₂— may be replaced by —CH═CH— or—C≡C—, and in the groups, at least one hydrogen may be replaced byfluorine or chlorine; g is 0, 1 or 2; h, j and k are independently 0, 1,2, 3 or 4; and a sum of h, j and k is 1 or more.
 15. The liquid crystalcomposition according to claim 11, wherein, in formula (5), P¹, P² andP³ are independently a group selected from the group of polymerizablegroups represented by formula (p-1) to formula (p-5):

wherein, in formula (p-1) to formula (p-5), M¹, M² and M³ areindependently hydrogen, fluorine, alkyl having 1 to 5 carbons, or alkylhaving 1 to 5 carbons in which at least one hydrogen is replaced byfluorine or chlorine.
 16. The liquid crystal composition according toclaim 1, containing at least one compound selected from the group ofpolymerizable compounds represented by formula (5-1) to formula (5-27)as an additive:

wherein, in formula (5-1) to formula (5-27), P⁴, P⁵ and P⁶ areindependently a group selected from the group of polymerizable groupsrepresented by formula (P-1) to formula (P-3):

wherein, in formula (P-1) to formula (P-3), M¹, M² and M³ areindependently hydrogen, fluorine, alkyl having 1 to 5 carbons, or alkylhaving 1 to 5 carbons in which at least one hydrogen is replaced byfluorine or chlorine; and in formula (5-1) to formula (5-27), Sp¹, Sp²and Sp³ are independently a single bond or alkylene having 1 to 10carbons, and in the alkylene, at least one —CH₂— may be replaced by —O—,—COO—, —OCO— or —OCOO—, and at least one —CH₂—CH₂— may be replaced by—CH═CH— or —C≡C—, and in the groups, at least one hydrogen may bereplaced by fluorine or chlorine.
 17. The liquid crystal compositionaccording to claim 11, wherein a proportion of the additive is in therange of about 0.03% by weight to about 10% by weight.
 18. A liquidcrystal display device, including the liquid crystal compositionaccording to claim
 1. 19. The liquid crystal display device according toclaim 18, wherein an operating mode in the liquid crystal display deviceincludes an IPS mode, a VA mode, an FFS mode or an FPA mode, and adriving mode in the liquid crystal display device includes an activematrix mode.
 20. A polymer sustained alignment mode liquid crystaldisplay device, wherein the device includes the liquid crystalcomposition according to claim 11, or a polymerizable compound in theliquid crystal composition is polymerized.